Guanylyl cyclases, nitric oxide, natriuretic peptides, and airway smooth muscle function
Ahmed M. Hamad,1
Andrew Clayton,2
Baharul Islam,2 and
Alan J. Knox2
1Department of Respiratory Medicine, Al-Mansourah University, Al-Dakahlia 3511, Egypt; and 2Department of Respiratory Medicine, University of Nottingham, Nottingham NG5 1PB, United Kingdom
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ABSTRACT
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Airway smooth muscle (ASM) plays an important role in asthma pathophysiology through its contractile and proliferative functions. The cyclic nucleotides adenosine 3',5'-cyclic monophosphate (cAMP) and guanosine 3',5'-cyclic monophosphate (cGMP) are second messengers capable of mediating the effects of a variety of drugs and hormones. There is a large body of evidence to support the hypothesis that cAMP is a mediator of the ASM's relaxant effects of drugs, such as
2-adrenoceptor agonists, in human airways. Although most attention has been paid to this second messenger and the signal transduction pathways it activates, recent evidence suggests that cGMP is also an important second messenger in ASM with important relaxant and antiproliferative effects. Here, we review the regulation and function of cGMP in ASM and discuss the implications for asthma pathophysiology and therapeutics. Recent studies suggest that activators of soluble and particulate guanylyl cyclases, such as nitric oxide donors and natriuretic peptides, have both relaxant and antiproliferative effects that are mediated through cGMP-dependent and cGMP-independent pathways. Abnormalities in these pathways may contribute to asthma pathophysiology, and therapeutic manipulation may complement the effects of
2-adrenoceptor agonists.
atrial natriuretic peptide; guanosine 3',5'-cyclic monophosphate; asthma
RECENT STUDIES HAVE SHOWN that both nitric oxide (NO) and atrial natriuretic peptide (ANP) have a significant bronchodilator effect in asthmatic subjects. Because NO and ANP share a common intracellular second messenger mechanism (i.e., cGMP), this suggests that cGMP may have important regulatory functions in human airway smooth muscle (ASM). Guanylyl cyclases (GC) are the enzymes that catalyze the conversion of GTP to guanosine cGMP and exist as soluble and particulate membrane-associated enzymes. NO is the natural activator of soluble GC, and a large part of this review will focus on its functions. Recent studies showed that carbon monoxide and pituitary adenylate cyclase-activating peptide can also activate soluble GC and relax guinea pig airways in vitro (15, 16, 110), but these are not discussed in detail here. Particulate GC act as plasma membrane receptors for natriuretic peptides and related peptides. Several membrane forms of the enzyme have been identified up to now. Some of them serve as receptors for the natriuretic peptides, a family of peptides that includes ANP, brain natriuretic peptide (BNP), and C-type natriuretic peptide (CNP), three peptides known to play important roles in renal and cardiovascular physiology. The type of GC present varies from tissue to tissue. In some tissues, the concentration of the soluble GC to particulate GC is nearly equal, whereas in others, such as the small intestine, the particulate form predominates (23). In some organs, such as the kidney, the relative abundance of both forms varies throughout the organ (22). However, the relative expression of different isoforms of GC in the lung have not been studied directly. This review will discuss the importance of cGMP as a second messenger in ASM, focusing on recent studies of soluble and particulate GC activators in intact and cultured ASM in vitro and in asthmatic subjects in vivo.
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NO AND SOLUBLE GC
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NO synthesis from the semiessential amino acid L-arginine is catalyzed by a family of enzymes called nitric oxide synthases (NOS). There are at least three isoforms of NOS that have been cloned and sequenced (37, 72, 83). There are two constitutive isoforms [constitutive NOS (cNOS)]: the endothelial isoform (endothelial NOS) or type III NOS, normally present in endothelial cells, and the neuronal isoform (neuronal NOS) or type I NOS, present in neuronal cells of the brain and the peripheral nerves. The constitutive isoforms are calcium dependent and induce transient production of picomolar concentrations of NO in response to various physiological stimuli. In contrast, the inducible isoform [inducible NOS (iNOS)] is upregulated in a number of cells, including airway epithelium, by endotoxins or cytokines (8, 102). This isoform generates larger (nanomolar) concentrations of NO for a more sustained period of time than cNOS (40). It is generally thought that iNOS is calcium independent. This has, however, been questioned by a recent report showing that iNOS contains calmodulin that is tightly bound and only requires very low levels of calcium for activation, merely giving the impression that it is calcium independent (18). In contrast, cNOS binds calmodulin loosely and requires much higher cytosolic levels of calcium to produce closer association with calmodulin, a step necessary for NO production. In the lung, vascular endothelial cells, macrophages, airway nerves [inhibitory nonadrenergic noncholinergic (iNANC)], and airway epithelium are thought to be the main sources of NO under basal conditions (40).
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SOLUBLE GC
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Soluble GC is a heterodimeric heme-containing cytosolic enzyme comprising large (
-) and small (
-) subunits; three isoforms for the
- (
1-
3) and
- (
1-
3) subunits have already been cloned and sequenced (81). The
1/
1 form, which is the universal form with greatest activity, has been cloned from the rat and bovine lung (70, 82). Each subunit is divided into three functional domains: a heme-binding domain (confers NO sensitivity), a catalytic domain (identical between the subunits and also to the catalytic domain of particulate GC), and a dimerization domain (mediating the subunits' association to form a heterodimer that is obligatory for enzyme activation) (48). Thiols are required for soluble GC activation by NO by forming more stable S-nitrosothiols with NO, and this may explain the inhibition of soluble GC by oxidizing agents such as methylene blue (39). The main effector cells for the effect of NO in the lung are vascular smooth muscle and ASM. Soluble GC, the primary receptor for NO, has been localized in the bronchial and vascular smooth muscle in the lung from various species (12, 70, 82, 97). Our own studies show that human airway smooth muscle cells (HASMC) express active soluble GC and accumulate cGMP after treatment with NO donors such as S-nitroso-N-acetyl penicillamine (SNAP) and sodium nitroprusside (SNP) (45).
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DESENSITIZATION OF SOLUBLE GC
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There is much literature on the use of NO donors as beneficial drugs for the treatment of acute forms of coronary artery disease. The major limitation of their use in vascular diseases is the rapid development of tolerance. This might also be a limitation in their effect on airways, although this has not been studied to the same extent. Several mechanisms for tolerance to the effects of nitrates have been suggested in different biological systems, including: 1) impaired biotransformation of organic nitrates to NO due to depletion of intracellular thiols (80), 2) increased cGMP breakdown due to increased phosphodiesterase (PDE) activity (79), or 3) impaired cGMP formation due to desensitization of soluble GC (112, 122). Studies from our group have looked at tolerance to the effect of NO donors in cultured human airway smooth muscle (Fig. 1). We showed that soluble GC is desensitized in HASMC after pretreatment with NO donors, leading to a decrease in cGMP accumulation in response to subsequent treatment with NO donors in a dose- and time-dependent manner (46). The same phenomenon was seen in cell-free preparations, suggesting a GC desensitization instead of changes in NO release from the NO donors used.

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Fig. 1. Theoretical mechanisms whereby desensitization of guanylyl cyclases (GC) might contribute to asthma pathophysiology. Proinflammatory cytokines and mediators in the asthmatic airways activate protein kinase C (PKC), which in turn desensitizes the particulate GC in airway smooth muscle (ASM). Proinflammatory cytokines and mediators may also induce inducible nitric oxide (NO) synthase (iNOS), which produces NO in excess amounts. This excess NO desensitizes soluble GC in ASM. Desensitization of either form of GC will lead to loss of the beneficial effects of cGMP in ASM, namely relaxation and inhibition of proliferation.
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WHAT ARE THE BIOLOGICAL EFFECTS OF SOLUBLE GC ACTIVATORS ON ASM FUNCTION?
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Contraction. A number of studies have looked at exogenously applied NO both in vitro and in vivo (Tables 1 and 2). There is a general agreement among in vitro studies that NO relaxes airway smooth muscle with a potency intermediate between the
-adrenoceptor agonist isoprenaline and the PDE inhibitor theophylline (19, 25, 59, 78, 106, 107). Endogenous NO from several sources in the airway is capable of regulating bronchomotor tone. Epithelium-derived relaxing factor (EpDRF), a NO or NO-like substance, is a relaxant of ASM from a number of species. Exogenous NO is a weak bronchodilator in vivo (Table 2). NOS inhibition enhances agonist-induced increase in airway resistance in guinea pig, supporting a role for EpDRF in control of bronchomotor tone (87, 101, 128). Consistent with this, NOS inhibition enhances agonist responses in guinea pig trachea with intact mucosa but not in epithelially denuded preparations (34, 87). Moreover, bradykinin increased cGMP and relaxed guinea pig trachea with intact epithelium but contracted epithelium-denuded trachea, suggesting that bradykinin stimulated the release of NO from the tracheal epithelium that in turn elevated cGMP levels and caused relaxation (34, 128). Studies in bovine trachea showed that NOS inhibition increased the basal tone, abolished histamine-induced increase in NO release from the epithelial layer, and enhanced histamine-induced contraction (107). More recent studies showed that repeated antigen exposure led to bronchial hyperresponsiveness in guinea pigs, probably due to a lack of EpDRF-mediated bronchodilatation (74). Indeed, clinical studies with NOS inhibitors in asthmatic subjects support this notion (99, 100). Furthermore, a recent study using human bronchial strips showed that the antiasthmatic affect of ginsenoside, an extract of Panax ginseng, is via stimulation of NO generation from airway epithelium and cGMP synthesis (119).
NO may also be produced endogenously by iNANC nerves and act locally on ASM. The iNANC mechanism is the only known neural bronchodilator pathway in humans, and NO is the only known neurotransmitter of iNANC nerves in humans (10, 11, 30, 124). In vitro studies in human airway preparations showing that the iNANC response is associated with a selective increase in cGMP and that selective inhibition of cGMP-specific PDE enzyme enhances the iNANC response are consistent with it being mediated by NO-induced increases in cGMP (32, 124).
In vivo studies in different species, including humans, showed a bronchodilator effect for inhaled NO. Hogman and colleagues (50) showed that inhalation of 80 parts per million of NO increased the specific airway conductance in asthmatic subjects, although to a lesser extent than after
2-agonists. These findings were confirmed in subsequent studies (63, 109). Clinical trials with nitrovasodilators generally showed a weak bronchodilator effect, with the inhaled route being the most promising method of delivery. However, most studies report significant cardiovascular side effects (38, 76, 90).
The relaxant effect of NO in different species correlates well with cGMP elevation, suggesting a causal role for cGMP in mediating its relaxation (36, 57, 129). However, other work in ASM suggests alternative mechanisms may also operate, including direct activation of maxi-K+ channels (1), oxidation of intracellular contractile proteins, e.g., myosin head or regulatory proteins involved in contraction (64, 95), or decreased sensitivity to intracellular Ca2+ (91, 98). This was clarified in a recent study comparing the effects of two redox forms of NO, NO+ (liberated by SNAP) and NO · [liberated by 3-morpholinosydnonimine (SIN-1)], in human main stem bronchi and canine trachealis (60). The results of this study suggest that NO+ causes release of internal Ca2+ in a cGMP-independent fashion, leading to activation of the maxi-K+ channels and relaxation, whereas NO · relaxes the airways through a cGMP-dependent, Ca2+-independent pathway.
Proliferation. Although there is evidence to support a role for the NO-GC-cGMP pathway in the regulation of proliferation in other cell systems, including vascular smooth muscle (111), it was not known until recently whether NO has a similar role in ASM. We have shown that SNAP, a direct NO donor, inhibited the proliferation of cultured HASMC in response to serum and thrombin (42). The antiproliferative affect of NO in our study was likely to be cGMP mediated based on the fact that zaprinast, a selective PDE-5 inhibitor, enhanced this effect and that a cell-permeable cGMP analog (8-bromoguanosine 3',5'-cyclic monophosphate) also had an antiproliferative effect. Additional cGMP-independent mechanisms for NO's antiproliferative effect were suggested by the fact that cGMP analogs had a weaker effect than NO donors. A subsequent study looking at the mechanisms underlying the antiproliferative effect of NO in HASMC showed that NO inhibited proliferation in both G1 and S phases of the cell cycle (44). The G1 phase effect was cGMP dependent, whereas the S phase effect was due to cGMP-independent inhibition of ribonucleotide reductase (Fig. 2). More recently, the proliferative effects of endothelin-1 (ET-1), both alone and in combination with epidermal growth factor, and the effect of NO on the cell proliferation were investigated in cultured guinea pig bronchial smooth muscle (67). A NO donor, SIN-1, reduced the cell-proliferative effect of ET-1 in a concentration-dependent manner. A soluble GC inhibitor partly, but significantly, reversed the effect of SIN-1. Studies using NOS inhibitors have shown that HASMC express type I NOS and inhibition of NOS enhances DNA synthesis and cell proliferation (92).

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Fig. 2. Role of NO/soluble GC/cGMP (A) and natriuretic peptides/particulate GC/cGMP (B) in regulation of ASM functions. GC stimulation by activators leads to increased formation of cGMP in ASM cells. cGMP exerts its effects through activation of cGMP-dependent protein kinase, with subsequent phosphorylation of different proteins. NO-induced relaxation could be cGMP independent (direct activation of maxi-K+ channels, oxidation of intracellular contractile proteins, or decreased sensitivity to intracellular Ca2+). NO also inhibits proliferation by cGMP-independent inhibition of ribonucleotide reductase. Atrial natriuretic peptide (ANP) clearance receptors mediate cGMP-independent antiproliferative effect of ANP. BNP, brain natriuretic peptide; CNP, C-type natriuretic peptide.
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NATRIURETIC PEPTIDES AND PARTICULATE GC
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The natriuretic peptide family of hormones has an important role in salt and water homeostasis. The human natriuretic peptides include ANP, BNP, and CNP. At first, the sole source of ANP was thought to be the heart. It has been known for a long time that ANP is secreted from the atrial myocytes into the blood stream in response to distension or stretch of the atrial wall (105). Several more recent studies, however, show that the lung is another source of ANP in different species, including humans (7, 71, 108, 114). Studies in hamsters showed that the ANP gene is expressed mainly in the airway epithelium and smooth muscle, and, to a lesser extent, in the alveolar wall, muscular media of the pulmonary arteries, and extraparenchymal pulmonary veins (86). ANP and the other natriuretic peptides act on different particulate GC receptors. These are transmembrane proteins composed of a single transmembrane domain, a variable extracellular natriuretic peptide-binding domain, and a more conserved intracellular kinase homology domain (KHD) and catalytic domain. GC-A, the receptor for ANP and BNP, also named natriuretic peptide receptor-A or -1, has been studied widely. Its mode of activation by peptide ligands and mechanisms of regulation serve as prototypes for understanding the function of other particulate forms of GC. Activation of this enzyme by its ligand is a complex process requiring oligomerization, ligand binding, KHD phosphorylation, and ATP binding. Gene knockout and genetic segregation studies have provided strong evidence for the importance of GC-A in the regulation of blood pressure and heart and renal functions (68). Immunohistochemical studies have localized GC-A to the ASM and alveoli in bovine lung (65). However, specific receptors for ANP have not been sought directly in human lung. We have used pharmacological tools to characterize the presence of these receptors in cultured HASMC (45). In this study, we showed that treatment of HASMC with ANP, BNP, and CNP led to a time- and concentration-dependent increase of cGMP levels in these cells, suggesting that particulate GC is expressed in these cells. The order of potency seen in our experiments was: ANP
BNP > CNP, consistent with type A and B of particulate GC being present in these cells (GC-A > GC-B). Although heat-stable enterotoxin (GC-C ligand) did not affect cGMP over the time course of our experiments, suggesting that GC-C is not expressed in HASMCs, a recent study showed that treatment of guinea pigs with uroguanylin (a ligand of GC-C receptor in gastrointestinal tissue) significantly inhibited leukotriene C4-induced pulmonary changes in a dose-dependent manner (89). The disparity between this study and ours may reflect species differences.
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DESENSITIZATION OF PARTICULATE GC
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Similar to soluble GC, particulate GC may undergo homologous desensitization after prolonged exposure to ANP through a cGMP-independent mechanism (46). We further studied the mechanism of particulate GC desensitization in HASMC (43); pretreatment of HASMC with phorbol 12-myristate 13-acetate (PMA), a protein kinase C (PKC) activator, led to time- and concentration-dependent desensitization of ANP-stimulated cGMP accumulation. GF-109203X, a selective PKC inhibitor, blocked the PMA-induced desensitization but did not block ANP-induced desensitization. In addition, desensitization by PMA and ANP showed an additive effect.
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WHAT ARE THE BIOLOGICAL EFFECTS OF PARTICULATE GC ACTIVATORS ON ASM FUNCTION?
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Contraction. ANP has a direct relaxant effect associated with cGMP accumulation in guinea pig airway in vitro (24, 75, 125). BNP and CNP have similar effects in guinea pig airway preparations (117, 118). ANP is a potent relaxant of the intrinsic tone as well as tone induced by various agonists in guinea pig trachea (95, 125). However, it may be more effective in relaxing methacholine-than in leukotriene D4-induced tone (46). In rat tracheal tissue, atriopeptins cause a weak relaxation of intrinsic tone as well as carbachol-induced tone (33). In bovine tracheal smooth muscle, ANP and atriopeptins have a direct relaxant effect on the tone induced by various agonists (57, 58). The potency of ANP was intermediate between isoprenaline and SNP. Infused ANP has been shown to reverse and protect against agonist-induced bronchoconstriction in guinea pigs in vitro (31, 88). Similar results were shown in sheep (9). More recently, BNP and CNP were reported to have a similar effect as ANP on antigen-induced changes in lung resistance in sensitized guinea pigs; the rank of order of inhibitory potency was BNP = ANP > CNP (88).
ANP also relaxes human airways in vitro. ANP was reported to reverse and protect against methacholine-induced contraction of human bronchi (6, 20, 84). ANP was more potent than SNP and salbutamol (20). Data from human and guinea pig airways suggest that the ANP relaxant effect may be due to cGMP-dependent activation of large conductance Ca2+-activated K+ channel (24, 75). A number of studies have looked at the effect of ANP on lung function in both normal and asthmatic subjects in vivo. Infused ANP at a concentration producing plasma levels in the pathophysiological range had a significant bronchodilator effect in asthmatics (52). The effect of infused ANP was similar to that of nebulized
2-agonists, although it was shorter lived. High dose-inhaled ANP produced less bronchodilator effect compared with intravenous ANP (3, 55, 56). This can be explained by the rapid degradation of ANP by the neutral endopeptidases (NEP) within the airways (6). This was confirmed in a subsequent study in which NEP inhibition greatly enhanced the bronchodilator effect of ANP in asthmatics (4, 5). However, it was observed that short-term exercise and acute asthma were associated with a rise in the plasma level of ANP (54, 103), suggesting that ANP could have a physiological role in the regulation of the bronchomotor tone. This increase in ANP may be due to hypoxia-induced pulmonary vasoconstriction, leading to increased right atrial pressure (127).
Proliferation. As with NO, ANP inhibits proliferation in several cell lines, but until recently, its role in regulation of HASMC proliferation was not known. We have shown that human ANP1-28 (a GC activator), rat ANP (rANP)104-126 (which binds selectively to the ANP clearance receptors without elevating cGMP), and a cGMP analog had an antiproliferative effect in HASMC, suggesting that both cGMP-dependant and cGMP-independent mechanisms are involved in ANP's antiproliferative effect (42). Although we found that the human ANP1-28, like SNAP, had antiproliferative effects, it produced a smaller maximum effect. This difference in efficacy contrasts with relative abilities of ANP and SNAP to elevate cGMP (ANP > SNAP). This paradox suggests that compartmentalization of cGMP pools may enable cGMP generated by soluble GC to have a greater effect than that generated by particulate GC.
The lung is capable of synthesizing ANP (35, 41, 86), and both types of ANP receptors (GC-linked and clearance receptors) have been characterized and localized throughout the lung. In the heart, where more is known about the function of ANP, ANP release is stretch stimulated (28). Similarly, Springall et al. (115) suggested that stretch of rat pulmonary vein stimulates ANP release. Preliminary data support a similar stretch-dependent mechanism for ANP release in tracheal muscle of anesthetized sheep (93). Stretch-dependent release of ANP from ASM, occurring with deep inspiration, could lead to cGMP elevation with subsequent inhibition of ASM tone and proliferation.
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CROSS TALK BETWEEN CGMP AND CAMP PATHWAYS
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The other main cyclic nucleotide involved in ASM relaxation is cAMP, which is activated mainly by
2-adrenoceptor agonists (69). In the classic pathway,
2-adrenoceptor agonists bind to
2-receptors, which are coupled to adenylyl cyclase, leading to production of cAMP. cAMP then activates protein kinase A (PKA), and PKA phosphorylates a number of substrates to bring about its intracellular effects (94, 113). In parallel pathways, NO and ANP activate soluble and particulate GC, respectively, to produce cGMP, and cGMP activates protein kinase G (PKG), which then phosphorylates its own set of substrates (94, 113, 120). It has become clear, however, that the situation is much more complex, and although it has not been studied in detail in ASM, cross talk between cGMP and cAMP pathways is well recognized in many other biological systems (94, 113). This cross talk can occur at a number of levels.
First, cyclic nucleotides can repress the degradation of their counterparts through their actions on PDEs (120). For example, the cGMP-stimulated PDE-2 and the cGMP-inhibited PDE-3 preferentially hydrolyze cAMP (94, 113, 120). Both of these PDE isozymes are present in human airway smooth muscle (120). Second, cGMP and cAMP are both capable of cross-activating their respective kinases. For example, at physiological concentrations, both cGMP and cAMP can activate PKG in vascular smooth muscle (21). In contrast, in the same experiments, PKA was only activated by cAMP. Other investigations have, however, shown that cGMP can inhibit proliferation of cultured vascular smooth muscle by activating PKA (26). In contrast, cAMP relaxes pig coronary arteries via PKG (62). Third, both PKG and PKA have a number of common substrates. Sites of phosphorylation in ASM for PKA include phospholipase C, maxi-K+ channels, Na+-K+-ATPase, myosin light chain kinase, and sarcoplasmic reticulum Ca2+ pumps. PKG can phosphorylate maxi-K+ channels and Ca2+ uptake pumps in ASM, and in non-ASM cells, contractile proteins and phospholipase C can also be phosphorylated (reviewed in Ref. 69). There is also evidence that PKA and PKG may cooperatively phosphorylate some substrates such that phosphorylation by one kinase changes the conformation of the target protein, making serine threonine sites more accessible to the other kinase (94). Alternatively, PKG or PKA may regulate the activity of protein phosphatases, which then modifies the effect of the other kinase (94). Finally, cross talk in some systems occurs in the regulation of cGMP/cAMP synthesis (77).
Although cross talk can be complex, compartmentalization within the cell of the enzymes catalyzing cyclic nucleotide synthesis and degradation, the enzymes responsible for cyclic nucleotide-mediated phosphorylation and the protein targets of these kinases exert a degree of constraint and allows cell specificity in the interactions and functional responses (94).
Collectively, these studies suggest there is considerable potential for pathways activated by NO donors or natriuretic peptides to enhance the effects of
2-adrenoceptor agonists either on relaxation or proliferation of ASM. Further studies addressing possible interactions in vitro may be of great interest. The demonstration of an additive effect of NO and NO donors on
2-agonist-induced bronchodilation in asthmatic subjects (50, 104) and that a combination of ANP and salbutamol evokes a greater effect than either alone in reversing and protecting against methacholine-evoked contraction in isolated human bronchi (84) suggest that such combinations could be of benefit in the treatment of asthma, allowing lower doses of each individual drug to be used.
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RELEVANCE OF GC TO ASTHMA
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The evidence reviewed thus far suggests that both soluble and particulate GC may have important roles in asthma pathophysiology but that NO donors and natriuretic peptides act through a combination of cGMP-dependent and cGMP-independent effects. NO donors and natriuretic peptides have ASM relaxant properties that may be important under different physiological circumstances. NO produced by NOS may have a physiological role in reducing ASM proliferation. The epithelial shedding that occurs in the asthmatic airways could, therefore, lead to the removal of a paracrine braking mechanism acting to inhibit ASM proliferation.
The desensitization seen with NO may also have pathophysiological significance. Numerous studies have shown that NO is produced in large quantities in asthmatic airways, possibly as a result of iNOS induction (126). This excess NO could potentially desensitize soluble GC in ASM, thereby impairing NO-mediated bronchodilatation (Fig. 1). This may be particularly important for the iNANC nervous system in which NO is the major neurotransmitter. Consistent with this hypothesis, there is some evidence that iNANC is dysfunctional in asthmatic airways (78). In this study, guinea pigs were sensitized with ovalbumin and then challenged with ovalbumin for 3 consecutive days. On the day after the final challenge, iNANC responses elicited by electrical field stimulation or relaxation responses to SIN-1 were obtained in the tracheal strips precontracted by histamine. The iNANC responses and SIN-1-induced relaxation of the ovalbumin group were significantly attenuated, suggesting that allergic airway inflammation impairs neural NO-induced relaxation, presumably by inhibiting the access of neural NO to the ASM (Fig. 1).
Our studies with ANP suggest that PKC activation can desensitize particulate GC but that the desensitization induced by ANP itself is PKC independent. The pathophysiological relevance of this desensitization is not clear, but it is possible that PKC activation by proinflammatory cytokines in asthma may downregulate the bronchoprotective effect of ANP.
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CONCLUSION
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Agents acting through cGMP could prove to be adjunctive therapy to the bronchodilators in current use. They utilize a complementary pathway to
-agonists, which signal through cAMP and anticholinergics that act specifically to block muscarinic cholinergic receptors. The demonstration of an additive effect of NO donors and
2-agonists, in some studies, suggests that such combinations could be of benefit in the treatment of asthma, allowing lower doses of each individual drug to be used. An alternative strategy might be to utilize S-nitrosylated derivatives of existing bronchodilator molecules. Interestingly, it was shown that S-nitrosylated derivatives of vasoactive intestinal peptide preserve the intrinsic function of vasoactive intestinal peptide but acquire NO-like vasoactivity when tested on aortic rings (61). Similar studies in the airways would be interesting. Currently, there is a great deal of interest in developing PDE inhibitors with a more favorable pharmacological profile than existing agents. The combined use of PDE inhibitors and GC activators could allow the use of smaller doses of both (32). It is also possible that the transient effects of ANP could be prolonged either by the concomitant use of NEP inhibitors or pharmacological modification of the ANP molecule.
Besides its relaxant effect, NO may also protect against airway remodeling by inhibiting ASM proliferation (an important component of airway thickening in asthma). Dysfunction of GC activation by endogenous stimuli may contribute to the bronchial hyperesponsiveness characteristic of asthma as asthmatic inflammation results in excess production of NO (Fig. 1). This excess NO would be expected to cause desensitization of soluble GC in ASM. Furthermore, activation of PKC as a result of asthmatic inflammation could desensitize particulate GC and impair cGMP production in response to endogenous natriuretic peptides (Fig. 1).
In conclusion, the GC/cGMP second messenger system has a parallel role to the adenylyl cyclase/cAMP system in ASM, regulating its contractile and proliferative functions. Drugs activating this pathway have the potential to be new antiasthma therapies that could be used in conjunction with existing drugs.
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DISCLOSURES
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A. M. Hamad was supported by an international research development grant from Wellcome Trust. A. Clayton was supported by a grant from the Medical Research Council (United Kingdom). B. Islam was supported by Wellcome Trust.
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FOOTNOTES
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Address for reprint requests and other correspondence: A. J. Knox, Dept. of Respiratory Medicine, City Hospital, Hucknall Road, Nottingham NG5 1PB, United Kingdom (E-mail: alan.knox{at}nottingham.ac.uk).
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REFERENCES
|
---|
- Abdelrahmane A, Salvail D, Dumoulin M, Garon J, Cadieux A, and Rousseau E. Direct activation of Kca channel in airway smooth muscle by nitric oxide: involvement of a nitrothiosylation mechanism? Am J Respir Cell Mol Biol 19: 485-497, 1998.[Abstract/Free Full Text]
- Angus RM, McCallum MJA, Hulks G, and Thomson NC. Bronchodilator, cardiovascular and cGMP response to high dose infused ANP in asthma. Am Rev Respir Dis 147: 1122-1125, 1993.[ISI][Medline]
- Angus RM, McCallum MJA, and Thomson NC. Effect of inhaled ANP on methacholine-induced bronchoconstriction in asthma. Clin Exp Allergy 24: 784-788, 1994.[ISI][Medline]
- Angus RM, Millar EA, Chalmer GW, and Thomson NC. Effect of inhaled ANP and a neutral endopeptidase inhibitor on histamine-induced bronchoconstriction. Am J Respir Crit Care Med 151: 2003-2005, 1995.[Abstract]
- Angus RM, Millar EA, Chalmer GW, and Thomson NC. Effect of inhaled thiorphan, a neutral endopeptidase inhibitor, on the bronchodilator response to inhaled ANP. Thorax 51: 71-74, 1996.[Abstract]
- Angus RM, Nally JE, McCall R, Young LC, McGrath JC, and Thomson NC. Modulation of the effect of atrial natriuretic peptide in human and bovine bronchi by phosphoramidon. Clin Sci (Lond) 86: 291-295, 1994.[ISI][Medline]
- Asai J, Nakazato M, Toshimori H, Matsukura S, Kangawa K, and Matsuo H. Presence of atrial natriuretic polypeptide in the pulmonary vein and vena cava. Biochem Biophys Res Commun 146: 1465-1470, 1987.[ISI][Medline]
- Asano K, Chee CBE, Gaston B, Lilly CM, Gerard C, and Stamler JS. Constitutive and inducible NOS gene expression, regulation, and activity in human lung epithelial cells. Proc Natl Acad Sci USA 91: 10089-10093, 1994.[Abstract/Free Full Text]
- Banerjee MR and Newman JH. Acute effects of ANP on lung mechanics and hemodynamics in awake sheep. J Appl Physiol 69: 728-733, 1990.[Abstract/Free Full Text]
- Belvisi MG, Stretton CD, Miura M, Verleden GM, Tadjkarimi S, Yacoub M, and Barnes PJ. Inhibitory NANC nerves in human tracheal smooth muscle: a quest for the neurotransmitter. J Appl Physiol 73: 2505-2510, 1992.[Abstract/Free Full Text]
- Belvisi MG, Stretton CD, Yacoub M, and Barnes PJ. NO is the endogenous neurotransmitter of bronchodilator nerves in humans. Eur J Pharmacol 210: 221-222, 1992.[ISI][Medline]
- Bloch KD, Filippov G, Sanchez LS, Nakane M, and De La Monte SM. Pulmonary soluble guanylyl cyclase, a nitric oxide receptor, is increased during the perinatal period. Am J Physiol Lung Cell Mol Physiol 272: L400-L406, 1997.[Abstract/Free Full Text]
- Byrick R, Hobbs E, Martineau R, and Nobel W. Nitroglycerin relaxes large airways. Anesth Analg 62: 421-425, 1983.[Abstract]
- Candenas ML, Naline E, Puybasset L, Devillier P, and Advenier C. Effect of ANP and atriopeptins on the human isolated bronchus. Comparison with the reactivity of the guinea pig isolated trachea. Pulm Pharmacol 4: 120-125, 1991.[ISI][Medline]
- Cardell LO, Lou YP, Takeyama K, Ueki IF, Lausier J, and Nadel JA. Carbon monoxide, a cyclic GMP-related messenger, involved in hypoxic bronchodilation in vivo. Pulm Pharmacol 11: 309-315, 1998.[ISI]
- Cardell LO, Ueki IF, Stjarne P, Agusti C, Takeyama K, Linden A, and Nadel JA. Bronchodilatation in vivo by carbon monoxide, a cyclic GMP related messenger. Br J Pharmacol 124: 1065-1068, 1998.[Abstract]
- Chanez P, Mann C, Bousquet J, and Chabrier PE. Atrial natriuretic factor (ANF) is a potent bronchodilator in asthma. J Allergy Clin Immunol 86: 321-324, 1990.[ISI][Medline]
- Cho HJ, Xie QW, Calaycay J, Mumford RA, Swiderek KM, Lee TD, and Nathan C. Calmodulin is a subunit of nitric oxide synthase from macrophages. J Exp Med 176: 599-604, 1992.[Abstract]
- Clayton RA, Nally JE, Thomson NC, and McGrath JC. Changing the oxygen tension alters the ability of bronchodilators to protect against methacholine-induced challenge in bovine isolated bronchial rings. Pulm Pharmacol 10: 51-60, 1997.[ISI]
- Clayton RA, Nally JE, Thomson NC, and McGrath JC. Interaction between endothelin-1 induced contraction and bronchodilators in human isolated bronchi. Clin Sci (Lond) 93: 527-533, 1997.[Medline]
- Cornwell TL, Arnold E, Boerth NJ, and Lincoln TM. Inhibition of smooth muscle cell growth by nitric oxide and activation of cAMP-dependent protein kinase by cGMP. Am J Physiol Cell Physiol 267: C1405-C1413, 1994.[Abstract/Free Full Text]
- Craven PA and Derubertis FR. Properties and subcellular distribution of guanylate cyclase activity in rat renal medulla: correlation with tissue content of guanosine 3',5'-monophosphate. Biochemistry 15: 5131-5137, 1976.[ISI][Medline]
- DeJong HR. Properties of guanylyl cyclase and levels of cyclic GMP in rat small intestinal villous and crypt cells. FEBS Lett 55: 143-152, 1975.[ISI][Medline]
- Devillier P, Corompt E, Breant D, Caron F, and Bessard G. Relaxation and modulation of cyclic AMP production in response to atrial natriuretic peptides in guinea pig tracheal smooth muscle. Eur J Pharmacol 430: 325-333, 2001.[ISI][Medline]
- Diamond J. Role of cGMP in airway smooth muscle relaxation. Agents Actions Suppl 43: 13-26, 1993.[Medline]
- Doerner D and Alger BE. Cyclic GMP depresses hippocampal Ca2+ current through a mechanism independent of cGMP-dependent protein kinase. Neuron 1: 693-699, 1998.
- Dupuy PM, Shore SA, Drazen J, Frostell CG, Hill WA, and Zapol WM. Bronchodilator action of inhaled NO in guinea pigs. J Clin Invest 90: 421-428, 1992.[ISI][Medline]
- Edwards BS, Zimmerman RS, Schwab TR, Heublein DM, and Burnett JC. Atrial stretch, not pressure, is the principal determinant controlling the acute release of atrial natriuretic factor. Circ Res 62: 191-195, 1988.[Abstract]
- Elias MD, de Lima WT, Vannuchi YB, Marcourakis T, da Silva ZL, Trezena AG, and Scavone C. Nitric oxide modulates Na+, K+-ATPase activity through cyclic GMP pathway in proximal rat trachea. Eur J Pharmacol 367: 307-314, 1999.[ISI][Medline]
- Ellis JL and Undem BJ. Inhibition by L-NG-nitro-L-arginine of nonadrenergic-noncholinergic-mediated relaxations of human isolated central and peripheral airways. Am Rev Respir Dis 146: 1543-1547, 1992.[ISI][Medline]
- Enghlebach IM, Lappe RW, and Hand JM. Bronchoprotective and bronchodilator activity of anaritide [human atrial natriuretic factor (102-126)] infusion in the anesthetized guinea pig. Pulm Pharmacol 1: 119-123, 1988.[Medline]
- Fernandes LB, Ellis JL, and Undem BJ. Potentiation of nonadrenergic noncholinergic relaxation of human isolated bronchus by selective inhibitors of phosphodiesterase isoenzymes. Am J Respir Crit Care Med 150: 1384-1390, 1994.[Abstract]
- Fernandes LB, Preuss JMH, and Goldie RG. Epithelial modulation of relaxant activity of atriopeptides in rat and guinea pig tracheal smooth muscle. Eur J Pharmacol 212: 187-194, 1992.[ISI][Medline]
- Figini M, Ricciardolo FL, Javdan P, Nijkamp FP, Emanueli C, Pradelles P, Folkerts G, and Geppetti P. Evidence that epithelium-derived relaxing factor released by bradykinin in the guinea pig trachea is nitric oxide. Am J Respir Crit Care Med 153: 918-923, 1996.[Abstract]
- Gardner DG, Deschepper CF, Ganong WF, Hane S, Fiddes J, Baxter JD, and Lewicki J. Extra-atrial expression of the gene for atrial natriuretic factor. Proc Natl Acad Sci USA 83: 6697-6701, 1986.[Abstract]
- Gaston B, Drazen J, Jansen A, Sugarbaker D, Loscalzo J, Richards W, and Stamler JS. Relaxation of human smooth muscle by S-nitrosothiols in vitro. J Pharmacol Exp Ther 268: 978-984, 1994.[Abstract]
- Geller DA, Lowenstein CJ, Shapiro RA, Nussler AK, Di Silvio M, Wang SC, Nakayama DK, Billiar TR, and Snyder SH. Molecular cloning and expression of inducible nitric oxide synthase from human hepatocytes. Proc Natl Acad Sci USA 90: 3491-3495, 1993.[Abstract]
- Goldstein JA. Nitroglycerin therapy of asthma. Chest 85: 449, 1984.
- Gruetter CA, Kadowitz PJ, and Ignarro LJ. Methylene blue inhibits coronary arterial relaxation and guanylate cyclase activation by nitroglycerin, sodium nitrate, and amyl nitrite. Can J Physiol Pharmacol 59: 150-156, 1981.[ISI][Medline]
- Guo FH, De Raeve HR, Rice TW, Stuehr DJ, Thunnissen FB, and Erzurum SC. Continuous nitric oxide synthesis by inducible nitric oxide synthase in normal human airway epithelium in vivo. Proc Natl Acad Sci USA 92: 7809-7813, 1995.[Abstract]
- Gutkowska G, Cantin M, Genest J, and Pierre S. Release of immunoreactive atrial natriuretic factor from the isolated perfused rat lung. FEBS Lett 214: 17-20, 1987.[ISI][Medline]
- Hamad AM, Johnson SR, and Knox AJ. Antiproliferative effects of NO and ANP in cultured human airway smooth muscle. Am J Physiol Lung Cell Mol Physiol 277: L910-L918, 1999.[Abstract/Free Full Text]
- Hamad AM and Knox AJ. Mechanisms involved in desensitization of particulate guanylyl cyclase in human airway smooth muscle: the role of protein kinase C. Biochem Biophys Res Commun 266: 152-155, 1999.[ISI][Medline]
- Hamad AM and Knox AJ. Mechanisms mediating the anti-proliferative effects of nitric oxide in cultured human airway smooth muscle cells. FEBS Lett 506: 91-96, 2001.[ISI][Medline]
- Hamad AM, Range SP, Holland E, and Knox AJ. Regulation of cyclic GMP by soluble and particulate guanylyl cyclases in cultured human airway smooth muscle. Am J Physiol Lung Cell Mol Physiol 273: L807-L813, 1997.[Abstract/Free Full Text]
- Hamad AM, Range SP, Holland E, and Knox AJ. Desensitization of guanylyl cyclases in cultured human airway smooth muscle cells. Am J Respir Cell Mol Biol 20: 1087-1095, 1999.[Abstract/Free Full Text]
- Hamel R and Ford-Hutchinson AW. Relaxant profile of synthetic ANF on guinea-pig pulmonary tissues. Eur J Pharmacol 121: 151-155, 1986.[ISI][Medline]
- Hobbs AJ. Soluble guanylate cyclase: the forgotten sibling. Trends Pharmacol Sci 18: 484-491, 1997.[ISI][Medline]
- Hogman M, Frostell CG, Arnberg H, and Hedenstierna G. Inhalation of NO modulates metacholine-induced bronchoconstriction in the rabbit. Eur Respir J 6: 177-180, 1993.[Abstract]
- Hogman M, Frostell CG, Hedenstrom H, and Hedenstierna G. Inhalation of NO modulates adult human bronchial tone. Am Rev Respir Dis 148: 1474-1478, 1993.[ISI][Medline]
- Hulks G, Jardine A, Connell JM, and Thomson NC. Influence of elevated plasma levels of atrial natriuretic factor on bronchial reactivity in asthma. Am Rev Respir Dis 143: 778-782, 1991.[ISI][Medline]
- Hulks G, Jardine A, Connell JM, and Thomson NC. Bronchodilator effect of atrial natriuretic peptide in asthma. BMJ 299: 1081-1082, 1989.[ISI][Medline]
- Hulks G, Jardine AJ, Connell JMC, and Thomson NC. Effect of atrial natriuretic factor on bronchomotor tone in the normal human airway. Clin Sci (Lond) 79: 51-55, 1990.[Medline]
- Hulks G, Mohammed AF, Jardine A, Connell JMC, and Thomson NC. Circulating plasma concentrations of atrial natriuretic peptide and catecholamines in response to maximal exercise in normal and asthmatic subjects. Thorax 46: 824-828, 1991.[Abstract]
- Hulks G and Thompson NC. High dose inhaled ANP is a bronchodilator in asthmatic subjects. Eur Respir J 7: 1593-1597, 1994.[Abstract/Free Full Text]
- Hulks G and Thomson NC. Inhaled atrial natriuretic peptide and asthmatic airways. BMJ 304: 1156, 1992.[ISI][Medline]
- Ijioma SC, Challis RAJ, and Boyle JP. Comparative effects of activation of soluble and particulate guanylyl cyclase on cGMP elevation and relaxation of bovine tracheal smooth muscle. Br J Pharmacol 115: 723-732, 1995.[Abstract]
- Ishii K and Murad F. ANP relaxes bovine tracheal smooth muscle and increases cGMP. Am J Physiol Cell Physiol 256: C495-C500, 1989.[Abstract/Free Full Text]
- Jansen A, Drazen J, Osborne JA, Brown R, Loscalzo J, and Stamler JS. The relaxant properties in guinea pig airways of S-nitrosothiols. J Pharmacol Exp Ther 261: 154-160, 1992.[Abstract]
- Janssen LJ, Premji M, Lu-Chao H, Cox G, and Keshavjee S. NO+ but not NO radical relaxes airway smooth muscle via cGMP-independent release of internal Ca2+. Am J Physiol Lung Cell Mol Physiol 278: L899-L905, 2000.[Abstract/Free Full Text]
- Jia L and Stamler JS. Dual actions of S-nitrosylated derivative of vasoactive intestinal peptide as a vasoactive intestinal peptide-like mediator and a nitric oxide carrier. Eur J Pharmacol 366: 79-86, 1999.[ISI][Medline]
- Jiang H, Colbran JL, Francis SH, and Corbin JD. Direct evidence for cross-activation of cGMP-dependent protein kinase by cAMP in pig coronary arteries. J Biol Chem 267: 1015-1019, 1992.[Abstract/Free Full Text]
- Kacmarek RM, Ripple R, Cockrill BA, Bloch KJ, Zappol WM, and Johnson DC. Inhaled nitric oxide. A bronchodilator in mild asthmatics with methocholine induced bronchospasm. Am J Respir Crit Care Med 153: 128-135, 1996.[Abstract]
- Kanthakumar K, Cundell DR, Johnson M, Wills PJ, Taylor GW, Cole PJ, and Wilson R. Effect of salmeterol on human nasal epithelial cell ciliary beating: inhibition of the ciliotoxin pyocyanin. Br J Pharmacol 112: 493-498, 1994.[Abstract]
- Kawaguchi S, Uchida K, Ito T, Kozuka M, Shimonaka M, Mizuno T, and Hirose S. Immunohistochemical localization of ANP receptor in bovine kidney and lung. J Histochem Cytochem 37: 1739-1742, 1989.[Abstract]
- Kennedy T, Summer WR, Sylvester J, and Robertson D. Airway response to sublingual nitroglycerin in acute asthma. JAMA 246: 145-147, 1981.[Abstract]
- Kizawa Y, Ohuchi N, Saito K, Kusama T, and Murakami H. Effect of endothelin-1 and nitric oxide on proliferation of cultured guinea pig bronchial smooth muscle cells. Comp Biochem Physiol C Pharmacol Toxicol Endocrinol 128: 495-501, 2001.
- Klinger JR, Warburton RR, Pietras LA, Smithies O, Swift R, and Hill NS. Genetic disruption of atrial natriuretic peptide causes pulmonary hypertension in normoxic and hypoxic mice. Am J Physiol Lung Cell Mol Physiol 276: L868-L874, 1999.[Abstract/Free Full Text]
- Knox AJ and Tattersfield AE. Airway smooth muscle relaxation. Thorax 50: 894-901, 1995.[ISI][Medline]
- Koesling D, Hartneck C, Humbert P, Bosserhoff A, Frank R, Schultz G, and Bohme E. The primary structure of the larger subunit of soluble guanylyl cyclase from bovine lung. FEBS Lett 266: 128-132, 1990.[ISI][Medline]
- Lofton CE, Baron DE, and Oehlenschlager WF. Pulmonary atrial natriuretic peptide. In: Biological and Molecular Aspects of Atrial Natriuretic Factors, edited by Needleman P. New York: Liss, 1988.
- Marsden PA, Heng HHQ, Scherer SW, Stewart RJ, Hall AV, Shi XM, Tsui LC, and Schappert T. Structure and chromosomal localization of the human constitutive endothelial nitric oxide synthase gene. J Biol Chem 168: 17478-17488, 1993.
- McAlpine LG, Hulks G, and Thomson NC. Effect of atrial natriuretic peptide given by intravenous infusion on bronchoconstriction induced by ultrasonically nebulized water (FOG). Am Rev Respir Dis 146: 912-915, 1992.[ISI][Medline]
- Mehta S, Drazen JM, and Lilly CM. Endogenous NO and allergic bronchial hyperresponsiveness in guinea pigs. Am J Physiol Lung Cell Mol Physiol 273: L656-L662, 1997.[Abstract/Free Full Text]
- Mikawa K, Kume H, and Takagi K. Effect of atrial natriuretic peptide and 8-bromo cyclic guanosine monophosphate on human tracheal smooth muscle. Arzneimittelforschung 48: 914-918, 1998.[ISI][Medline]
- Miller WC and Shultz TF. Failure of nitroglycerin as a bronchodilator. Am Rev Respir Dis 120: 471, 1979.
- Mittal CK, Braughler JM, Ichihara K, and Murad F. Synthesis of adenosine 3',5'-monophosphate by guanylate cyclase, a new pathway for its formation. Biochim Biophys Acta 585: 333-342, 1979.[ISI][Medline]
- Miura M, Yamauchi H, Ichinose M, Ohuchi Y, Kageyama N, Tomaki M, Endoh N, and Shirato K. Impairment of neural NO-mediated relaxation after exposure in guinea pig airways in vitro. Am J Respir Crit Care Med 156: 217-222, 1997.[Abstract/Free Full Text]
- Mullershausen F, Russwurm M, Thompson WJ, Liu L, Koesling D, and Friebe A. Rapid nitric oxide-induced desensitization of the cGMP response is caused by increased activity of phosphodiesterase type 5 paralleled by phosphorylation of the enzyme. J Cell Biol 155: 271-278, 2001.[Abstract/Free Full Text]
- Mulsch A, Busse R, and Bassenge E. Desensitization of guanylyl cyclase in nitrate tolerance does not impair endothelium-dependent responses. Eur J Pharmacol 158: 191-198, 1988.[ISI][Medline]
- Murad F. regulation of cytosolic guanylyl cyclase by nitric oxide: the NO-cyclic GMP signal transduction system. Adv Pharmacol 26: 19-33, 1994.[Medline]
- Nakane M, Arai K, Saheki S, Kuno T, Buechler W, and Murad F. Molecular cloning and expression of cDNAs coding for soluble guanylyl cyclase from rat lung. J Biol Chem 265: 16841-16845, 1990.[Abstract/Free Full Text]
- Nakane M, Schmidt HHHW, Pollock JS, Forstermann U, and Murad F. Cloned human brain nitric oxide synthase expressed in human skeletal muscle. FEBS Lett 316: 175-180, 1993.[ISI][Medline]
- Nally JE, Clayton RA, Thomson NC, and McGrath JC. The interaction of
-human atrial natriuretic peptide (ANP) with salbutamol, sodium nitroprusside and isosorbide dinitrate in human bronchial smooth muscle. Br J Pharmacol 113: 1328-1332, 1994.[Abstract]
- Nally JE, Doherty CC, Clayton RA, and Thomson NC. Bronchodilator and pre-protective effects of urodilatin in bovine bronchi in vitro: comparison with atrial natriuretic peptide. Br J Pharmacol 114: 1391-1396, 1995.[Abstract]
- Nardo PD, Minieri M, Sampaolesi M, Carbone A, Loreni F, Samuel JL, and Lauro R. Atrial natriuretic factor (ANF) and ANF receptor C gene expression and localization in the respiratory system: effects induced by hypoxia and hemodynamic overload. Endocrinology 137: 4339-4350, 1996.[Abstract]
- Nijkamp FP, van der Linde HJ, and Folkerts G. Nitric oxide synthesis inhibitors induce airway hyperresponsiveness in the guinea pig in vivo and in vitro: role of the epithelium. Am Rev Respir Dis 148: 727-734, 1993.[ISI][Medline]
- Ohbayashi H, Suiti H, and Takagi K. Compared effects of natriuretic peptides on ovalbumin-induced asthmatic model. Eur J Pharmacol 346: 55-64, 1998.[ISI][Medline]
- Ohbayashi H and Yamaki KI. Both inhalant and intravenous uroguanylin inhibit leukotriene C4-induced airway changes. Peptides 21: 1467-1472, 2000.[ISI][Medline]
- Okayama M, Sasaki H, and Takishima T. Bronchodilator effect of sublingual isosorbide dinitrate in asthma. Eur J Pharmacol 26: 151-155, 1984.
- Pabelick CM, Warner DO, Perkins WJ, and Jones KA. S-nitrosoglutathione-induced decrease in calcium sensitivity of airway smooth muscle. Am J Physiol Lung Cell Mol Physiol 278: L521-L527, 2000.[Abstract/Free Full Text]
- Patel HJ, Belvisi MG, Yacoub MH, Chung KF, and Mitchell J. Constitutive expressions of type I NOS in human airway smooth muscle cells: evidence for an antiproliferative role. FASEB J 13: 1810-1816, 1999.[Abstract/Free Full Text]
- Pearse DB, Wagner EM, and Permutt S. Trachealis muscle cGMP is increased by stretch in anesthetized sheep (Abstract). Am J Respir Crit Care Med 155: A545, 1997.
- Pelligrino DA and Wang Q. Cyclic nucleotide crosstalk and the regulation of cerebral vasodilation. Prog Neurobiol 56: 1-18, 1998.[ISI][Medline]
- Perkins WJ, Pabelick C, Warner DO, and Jones KA. Cyclic GMP-independent mechanism of airway smooth muscle relaxation induced by S-nitrosoglutathione. Am J Physiol Cell Physiol 275: C468-C474, 1998.[Abstract/Free Full Text]
- Potvin W and Varma DR. Bronchodilator activity of atrial natriuretic peptide in guinea pigs. Can J Physiol Pharmacol 67: 1213-1218, 1989.[ISI][Medline]
- Rengasamy A, Xue C, and Johns RA. Immunohistochemical demonstration of a paracrine role of NO in bronchial function. Am J Physiol Lung Cell Mol Physiol 267: L704-L711, 1994.[Abstract/Free Full Text]
- Rho EH, Perkins WJ, Lorenz RR, Warner DO, and Jones KA. Differential effects of soluble and particulate guanylyl cyclases on Ca2+ sensitivity in airway smooth muscle. J Appl Physiol 92: 257-263, 2002.[Abstract/Free Full Text]
- Ricciardolo FL, Di Maria GU, Mistretta A, Sapienza MA, and Geppetti P. Impairment of bronchoprotection by NO in severe asthma. Lancet 350: 1297-1298, 1997.[ISI][Medline]
- Ricciardolo FL, Geppetti P, Mistretta A, Nadel JA, Sapienza MA, Bellofiore S, and Di Maria GU. Randomized double-blind placebo-controlled study of the effect of inhibition of NO synthesis in bradykinin induced asthma. Lancet 348: 374-377, 1996.[ISI][Medline]
- Ricciardolo FL, Nadel JA, Yoishihara S, and Geppetti P. Evidence for reduction of bradykinin-induced brochoconstriction in guinea-pigs by release of NO. Br J Pharmacol 113: 1147-1152, 1994.[Abstract]
- Robbins RA, Barnes PJ, Springall DR, Warren JB, Kwon OJ, Buttery LD, Wilson AJ, Geller DA, and Polak JM. Expression of inducible nitric oxide synthase in human lung epithelial cells. Biochem Biophys Res Commun 203: 209-218, 1994.[ISI][Medline]
- Robichaud A, Michoud MC, Hamet P, and Du Souich P. Plasma atrial natriuretic peptide during spontaneous bronchoconstriction in asthmatics. Peptides 16: 653-656, 1995.[ISI][Medline]
- Rolla G, Brussino L, Colagrande P, and Bucca C. Additive effect of nitroglycerin inhalation on
2-agonist-induced bronchodilation in asthmatics. Pulm Pharmacol 8: 137-141, 1995.[ISI][Medline]
- Ruskoahe H. Atrial natriuretic peptide: synthesis, release and metabolism. Pharmacol Rev 44: 479-602, 1992.[ISI][Medline]
- Sadeghi-Hashjin G, Folkerts G, Hendrick DJ, van de Loo PGF, van der Linde HJ, Dik IEM, and Nijkamp FP. Induction of guinea pig airway hyperresponsiveness by inactivation of guanylyl cyclase. Eur J Pharmacol 302: 109-115, 1996.[ISI][Medline]
- Sadeghi-Hashjin G, Henricks PAJ, Folkerts G, Verheyen AKCP, van der Linde HJ, and Nijkamp FP. Bovine tracheal responsiveness in vitro: role of the epithelium and nitric oxide. Eur Respir J 9: 2286-2293, 1996.[Abstract/Free Full Text]
- Sakamoto M, Nakao K, Morii A, Sugawara A, Yamada T, Itoh H, Shiono S, Saito Y, and Imura H. The lung as a possible target organ for atrial natriuretic polypeptide secreted from the heart. Biochem Biophys Res Commun 135: 515-520, 1985.[ISI]
- Sanna A, Kurtansky A, Veriter C, and Stanescu D. Bronchodilator effect of inhaled NO in healthy men. Am J Respir Crit Care Med 150: 1702-1704, 1994.[Abstract]
- Saotome M, Uchida Y, Nomura A, Endo T, and Hasegawa S. Pituitary adenylate cyclase activating peptide induces cGMP-mediated relaxation in guinea pig airways. Pulm Pharmacol 11: 281-285, 1998.[ISI]
- Sarkar R and Webb RC. Does nitric oxide regulate smooth muscle cell proliferation? J Vasc Res 35: 135-142, 1998.[ISI][Medline]
- Schroeder H, Leitman DC, Bennett BM, Waldman SA, and Murad F. Nitroglycerin-induced desensitization of guanylate cyclase in cultured rat lung fibroblasts. J Pharmacol Exp Ther 245: 413-418, 1988.[Abstract]
- Schwede F, Maronde E, Genieser H, and Jastorff B. Cyclic nucleotide analog as biochemical tools and prospective drugs. Pharmacol Ther 87: 199-226, 2000.[ISI][Medline]
- Sirois P and Gutkowska J. Atrial natriuretic factor immunoreactivity in human fetal lung tissue and perfusates. Hypertension 11: 162-165, 1988.
- Springall DR, Bhatnagar M, Wharton J, Hamid Q, Gulbenkian S, Hedges M, Meleagros L, Bloom SR, and Polak JM. Expression of the atrial natriuretic peptide gene in the cardiac muscle of rat extrapulmonary and intrapulmonary veins. Thorax 43: 44-52, 1988.[Abstract]
- Stuart-Smith K, Warner DO, and Jones KA. The role of cyclic GMP in the relaxation to nitric oxide donors in airway smooth muscle. Eur J Pharmacol 241: 225-233, 1998.
- Takagi K and Araki N. Relaxant effects of BNP on guinea pig tracheal smooth muscle. Clin Exp Pharmacol Physiol 20: 239-243, 1993.[ISI][Medline]
- Takagi K, Araki N, and Suzuki K. Relaxant effect of C-type natriuretic peptide on guinea-pig tracheal smooth muscle. Arzneimittelforschung 42: 1329-1331, 1992.[Medline]
- Tamaoki J, Nakata J, Kawatani K, Tagaya E, and Nagai A. Ginsenoside-induced relaxation of human bronchial smooth muscle via release of nitric oxide. Br J Pharmacol 130: 1859-1864, 2000.[Abstract/Free Full Text]
- Torphy TJ. Phosphodiesterase isozymes: molecular targets for novel antiasthma agents. Am J Respir Crit Care Med 157: 351-370, 1998.[ISI][Medline]
- Tullett WM and Patel KR. Isosorbide dinitrate and isoxsuprine in exercise-induced asthma. Br Med J 280: 1934-1935, 1983.
- Waldman SA, Rapoport RM, Ginsburg RM, and Murad F. Desensitization to nitroglycerin in vascular smooth muscle from rat and human. Biochem Pharmacol 35: 3523-3531, 1986.
- Ward JK, Barnes PJ, Springall DR, Abelli L, Tadjkarimi S, Yacoub M, Polak JM, and Belvisi MG. Distribution of human i-NANC broncodilator and NO-immunoreactive nerves. Am J Respir Cell Mol Biol 13: 175-184, 1995.[Abstract]
- Ward JK, Barnes PJ, Tadjkarimi S, Yacoub M, and Belvisi MG. Evidence for the involvement of cGMP in neural bronchodilator responses in human trachea. J Physiol 483: 525-536, 1995.[Abstract]
- Watanabe H, Suzuki K, Takagi K, and Satake T. Mechanism of atrial natriuretic peptide and sodium nitroprusside-induced relaxation in guinea-pig tracheal smooth muscle. Arzneimittelforschung 40: 771-776, 1990.[Medline]
- Watkins DN, Peroni DJ, Basclain KA, Garlepp MJ, and Thompson PJ. Expression and activity of nitric oxide synthases in human airway epithelium. Am J Respir Cell Mol Biol 16: 629-639, 1997.[Abstract]
- Yalkut D, Lee LY, Grider J, Jorgensen M, Jackson B, and Ott C. Mechanism of atrial natriuretic peptide release with increased inspiratory resistance. J Lab Clin Med 128: 322-328, 1996.[ISI][Medline]
- Yoshihara S, Nadel JA, Figini M, Emanueli C, Pradelles P, and Geppetti P. Endogenous nitric oxide inhibits bronchoconstriction induced by cold-air inhalation in guinea pigs. Am J Respir Crit Care Med 157: 547-552, 1998.[ISI][Medline]
- Zhou H and Torphy TJ. Relationship between cGMP accumulation and relaxation of canine trachealis induced by nitrovasodilators. J Pharmacol Exp Ther 258: 972-978, 1991.[Abstract]