Reproductive Endocrinology and Family Welfare Research Unit, Department of Human Physiology with Community Health, Vidyasagar University, Midnapore-721 102, West Bengal, India
Received February 10, 2003; accepted July 2, 2003
![]() |
ABSTRACT |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Key Words: sodium arsenite; sodium selenite; steroidogenesis; brain monoamines; peroxidase; ovarian follicles.
![]() |
INTRODUCTION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Free radicals and reactive oxygen species are produced in the metabolic processing of arsenical compounds (Tabacova et al., 1992; Yamanaka et al., 1990
), which may lead to DNA single-strand breakage and DNAprotein cross-link via the formation of apurinic/apyrimidinic (AP) sites through a Schiff-based reaction between amino groups of nuclear protein, particularly histone (H1) and nonhistone proteins and aldehyde groups of AP sites in DNA (Kato et al., 1994
).
On the other hand, the potential of dietary antioxidants (such as vitamin C, vitamin E, and ß-carotene) to reduce the activity of radical-induced reactions during any kind of stress has drawn increasing attention in recent years (McCall and Balz, 1999). In addition, the in vivo detoxification of arsenic is one of the challenging issues in this decade. Some researchers have shown that selenium may play an important role in arsenic detoxification from living cells. Dietary supplementation with sodium selenite significantly reduces the clastogenic and genotoxic effects of arsenic (Beckman and Nordenson, 1986
; Biswas et al., 1999
). An arsenic-induced chromosomal aberration of cultured lymphocytes was reduced in smelter workers after treatment with selenium (Hu, 1989
); there are data that suggest that selenium is able to antagonize arsenic-mediated inhibition of DNA synthesis in human peripheral lymphocytes (Hu et al., 1996
). Alteration of heme oxygenase in human red blood cell (RBC) by sodium arsenite is prevented by selenium (Taketani et al., 1991
). Concomitant administration of selenium and gallium arsenide suggested that selenium has some beneficial role in the prevention of the appearance of signs of gallium arsenide toxicity by obstructing the inhibition of blood
-amino levulinic acid dehydratase as well as hepatic malondialdehyde formation and finally blocking the accumulation of gallium and arsenic (Flora et al., 1999
). We have already established that antioxidants like vitamins E and C are able to reduce arsenic-mediated ovarian and uterine toxicity (Chattopadhyay et al., 2000
, 2001
). However, there is a paucity of information regarding the role of selenium in arsenic-mediated ovarian-gametogenic and steroidogenic dysfunction, even though selenium is an essential dietary component for the maintenance of mammalian reproduction (Basini and Tamanini, 2000
; Bleau et al., 1984
; Kaur et al., 1999
). Therefore the present study was aimed at examining whether selenium in the form of sodium selenite has any significant role on arsenic-mediated changes in steroidogenic status and ovarian-uterine dysfunction.
![]() |
MATERIALS AND METHODS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Drug treatments, selection of dose, study of estrous cycle, and sample collection.
Sodium arsenite and sodium selenite were obtained from Sigma Chemical Co. (St. Louis, MO). The animals were divided into three equal groups, with 18 animals per group, and their initial body weights were noted along with a record of their daily water consumption (about 10 ml/day). The animals of the first group received an oral daily dose of 0.4 ppm sodium arsenite dissolved in 10 ml of distilled drinking water for 28 days. Another group of animals received the same dose of sodium arsenite followed by dietary supplement of 0.6 mg of sodium selenite (mixed with 10 g of a standard diet)/100 g body weight/day. The control group was supplied with 10 ml of distilled water orally as a vehicle for 28 days. Each of the control and experimental groups were provided with separate water bottles, where pure water for the control rats and arsenic-contaminated water for experimental rats was given. The animals sucked the water from the respective bottles. Vaginal smears were collected twice daily (8:00 A.M. and 5:00 P.M.) from all of the animals. The smears were stained by eosin-haematoxylin and examined microscopically. The feeding habits of all of the animals were observed throughout the experimental schedule. All of the animals were sacrificed at the diestrous phase 20 h after the last arsenic treatment. The body weights of all of the animals were recorded on the day of sacrifice. Blood was collected from all of the animals from the dorsal aorta using a heparinized syringe (21-gauge needle) after a light ether anesthesia. Plasma samples were separated by centrifugation and stored at -20°C until all of the samples had been used for the determination of plasma levels of gonadotrophins and estradiol. The ovaries and uterus were dissected out, and the organs weights were measured on a single-pan electronic balance. The level of arsenic was analyzed in all of the organs by atomic absorption spectrometry. The ovaries from six animals of each experimental group were used for biochemical assay of ovarian delta five, 3 beta-hydroxysteroid dehydrogenase (5,3ß-HSD) and 17 beta-hydroxysteroid dehydrogenase (17ß-HSD) activities, whereas one ovary and one uterine horn from another six animals of each group were kept at -20°C for biochemical measurement of peroxidase activities. The other ovaries and uterine horns of each animal of the above-mentioned groups were used for histological study. The plasma, ovaries, and uterine horns of the remaining 6 animals of each group were kept ready to measure the elementary arsenic content. The brain of the animals of each experimental group was dissected out and very quickly transferred to a petri dish covered by ice. The whole midbrain and diencephalon were separated out in intact condition and immediately transferred at -20°C for spectrofluorometric estimation of brain monoamines. The livers and kidneys of all groups of animals were dissected out and frizzed for the assay of acid and alkaline phosphatase and assays of glutamic oxaloaccetate transaminase (GOT) and glutamic pyruvate transaminase (GPT).
Assay of ovarian 5,3ß-HSD and 17ß-HSD activities.
To study ovarian 5,3ß-HSD and 17ß-HSD activities, two ovaries from each of the six animals of each group were homogenized separately, maintaining chilling conditions (4°C) in 20% spectroscopic-grade glycerol containing 5 mM of potassium phosphate and 1 mM of EDTA at a tissue concentration of 10 mg/ml homogenizing mixture in a homogenizer (Remi RQ-127A, Mumbai, India). This mixture was centrifuged at 10,000 g for 30 min at 4°C in a cold centrifuge (AvantiTM 30, Beckman, USA). The supernatant was mixed with 1 ml of 100-µM sodium pyrophosphate buffer (pH 8.9) and 40 µl of 30 µg of dehydroepiandrosterone (DHEA), making the incubation mixture a total of 3 ml.
5,3ß-HSD activity was measured after the addition of 0.5 µM of NAD to the tissue supernatant mixture in a spectrophotometer (U-2001, Hitachi, Japan) at 340 nm against a blank (without NADP) (Talalay, 1962
). For ovarian 17ß-HSD activity measurements, the same supernatant fluid (1 ml) of homogenizing mixture was added with 440 µM of sodium pyrophosphate buffer (pH -10.2), bovine serum albumin (25 mg of crystalline BSA), and 0.3 µM of testosterone, making the incubation mixture a total of 3 ml. The enzyme activity (17ß-HSD) was measured (Jarabak et al., 1962
) after the addition of 1.1-µM nicotinamide adenine dinucleotide phosphate (NADP) to the tissue supernatant mixture in a spectrophotometer at 340 nm against a blank (without NADP). One unit of enzyme activity is equivalent to a change in absorbency of 0.001/min at 340 nm.
Estimation of serotonin (5-HT), dopamine (DA), and norepinephrine (NE).
Norepinephrine, dopamine, and serotonin were extracted after homogenizing the midbrain or diencephalon separately in acidified ice-cooled butanol (Das et al., 1990). These homogenizing mixtures were centrifuged separately at 4000 rpm. After centrifugation, a portion of butanol extract was processed for fluorescence development (Kent Shellenberger and Gordon, 1971
). The fluorescence of 5-HT was measured in the Perkin Elmer MPF 44B Spectrofluorometer with the excitation wavelength set at 385 nm and the emission spectra at 490 nm (Kent Shellenberger and Gordon, 1971
). A reading for DA was made at 4°C at 325 nm activation peak and fluorescence at 380 nm uncorrected (Kent Shellenberger and Gordon, 1971
).
The remaining portion of butanol extract was shaken with 0.1-M phosphate buffer, (pH 6.5) and then centrifuged. After processing for the development of fluorophobes (Kent Shellenberger and Gordon, 1971), the fluorescence of NE was read with the excitation wavelength at 380 nm and the emission spectra at 495 nm (Kent Shellenberger and Gordon, 1971
).
Study of ovarian and uterine peroxidase.
Ovarian and uterine peroxidase activities were measured spectrophotometrically (Sadasivan and Manickam, 1996). These tissues were homogenized separately in 0.1-M phosphate buffer solution (pH -7.0) at a tissue concentration of 10 mg/ml. Next, 20-mM guiacol was mixed with 0.1-ml supernatant collected from a homogenate. In the presence of 0.3 ml of 12.3 mM H2O2, the time was noted when the absorbency was increased (436 nm) by 0.1.
Biochemical assay of alkaline phosphatase and acid phosphatase.
For a quantitative estimation of alkaline phosphatase in the liver and kidney, these organs were homogenized separately in a Potter Elvijhem homogenizer using ice-cold homogenizing medium (0.22-M Tris, Hcl buffer pH 7.5) at a tissue concentration of 20 mg/ml; 0.25ml of homogenate then was added in a centrifuge tube containing 1-ml buffer (1-mM p-nitrophenol phosphate in 1-M Tris, buffer, pH -8.0). The mixture was incubated at 37±°C for 30 min in a water bath. The assay was based on the formation of p-nitrophenol (PNP) in the hydrolysis of p-nitrophenol phosphate (PNPP). The activity was measured spectrophotometrically at 420 nm using a visible spectrophotometer (Malymy and Horecker, 1966). Serum alkaline phosphatase was measured using the same buffer and 0.1 ml of serum (Malymy and Horecker, 1966
).
For determination of the acid phosphatase activity, the same homogenizing medium was used and the tissue concentration was as above. The acid phosphatase activity was measured in an acetate buffer at pH 4.5 using p-nitrophenol phosphate as a substrate (Vanha-Perttula and Nikkanen, 1973). Serum acid phosphatase was measured using the same buffer and a substrate with 0.1-ml serum added (Vanha-Perttula and Nikkanen, 1973
).
Biochemical assay of transaminases.
The liver and kidney GOT and GPT were measured by homogenizing their tissues in a phosphate buffer at pH 7.4 according to the method of Goel (1988).
Radioimmunoassay (RIA) of LH and FSH.
The plasma levels of LH and FSH were measured by RIA (Moudgal and Madhwa Raj, 1974) using reagents supplied by the Rat Pituitary Distribution Program and NIDDK (Bethesda, MD). Carrier-free 125I for hormone iodination was obtained from Bhaba Atomic Research Center (Mumbai, India). Pure rat FSH (NIDDK-rFSH-I-5) and LH (NIDDK-rLH-I-5) were iodinated using the Chloramine-T (Sigma Chemical Co., St.Loius, MO) (Greenwood et al., 1963
). NIDDK anti-rat FSH-S-11 and NIDDK anti-rat LH-S-5 were used as anti-sera at final dilutions of 1:2500 and 1:10,000, respectively. Goat anti-rabbit
-globulin was used as the second antibody. It was obtained from Indo-Medicine (Friendswood, TX). The intraassay variations were 5% and 6% for LH and FSH, respectively. All samples were run at a time to avoid interassay variation.
Radioimmunoassay of estradiol.
The plasma level of estradiol was assayed by a radioimmunoassay technique (Hanning et al., 1974). Methodological loss during extraction was monitored by adding 10,000 cpm {1ß, 2ß-3H(N)} estradiol before extraction with 4 ml of diethyl ether twice. The samples were assayed in duplicate. The anti-sera to estradiol were purchased from Endocrine Science (Tarzzana, CA), and it had 40% cross-reactivity with estrone. Using dextran-coated charcoal, free and bound estradiols were separated. The intraassay variation was 6.5%. All of the samples were run at the same time to avoid interassay variation. Since chromatographic purification of the samples was not performed, the values reported are the sum of estradiol and estrone.
Histological study of ovarian-uterine tissue and quantification study of folliculogenesis.
For the fixation of the ovary and uterine horn, Bouins fluid was used. Graded dehydration of the tissue was done by 70 to 100% alcohol in subsequent steps. Xylene was used as the clearing agent. The tissues were embedded in paraffin (58.6°C). Sections of paraffin blocks were cut by a rotatory microtome (5 µ). The sections were stained by eosine and haematoxylin and observed under a microscope.
The quantification study of folliculogenenesis was performed according to Patil et al.(1998). Diameters and morphologies of the follicles were used to classify the follicles as:
The follicles under regeneration were classified depending on the degree of regeneration. In stage IA, pyknosis in some granulosa cells is observed; in stage IB, degenerative changes occured in the entire granulosa cell layer; stage IIA was characterized by meiosis in metaphase I (pseudomaturation) and degenerating cumulus cells; and stage IIB was characterized by oocytes floating in the antrum with few pyknotic bodies.
The diameter of the uterine lumen along with the uterine epithelium height and the diameter of the endometrium and myometrium were measured under a microscope with the help of an ocular and stage micrometer at 10 x 10x magnification.
Determination of elemental arsenic content.
The arsenic contents in the plasma and ovarian and uterine tissues were measured by atomic absorption spectrometry (Locke, 1979; Nurenberg, 1982
). Twenty-five mg of ovarian tissue, 50 mg of uterine tissue, and 0.5 ml of plasma were allowed to fix in formaldehyde and dried at 150°C for 20 min to evaporate the formaldehyde. Next, samples were transferred inside quartz beakers, which had been washed with 1:1 HNO3 and H2SO4 solution. The samples were digested with a 2-ml pure nitric acid mixture inside a digestion chamber at 150°C for 20 min. Until a small volume was obtained, the beakers were capped and enclosed samples were boiled. Digested samples were filtered and diluted up to 25 ml with deionized distilled water. The same deionized water was used as blanks, and a reading was taken in a Varian AA-575 ABQ model of the atomic absorption spectrometer.
Statistical analysis.
Results of the experiments were expressed as mean and standard error of different groups. The differences between the mean values were evaluated by ANOVA followed by multiple Students t-test (Zar 1996). The values for p < 0.05 were considered significant.
![]() |
RESULTS |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
|
Ovarian Steroidogenic Key Enzymes Activities
Twenty-eight days of arsenic treatment significantly suppressed ovarian 5,3ß-HSD and 17ß-HSD activities in comparison with the controls. The concomitant administration of sodium arsenite with a sodium selenitemixed diet resulted in enzymatic activities similar to the control level (Fig. 1
).
|
|
|
|
|
|
Arsenic Content in Plasma and Female Sex Organs of Rat
The group treated with arsenic alone showed a significant elevation in arsenic deposition in the ovary and uterus as well as in the plasma when compared with the control group (Table 5). However, with selenium supplementation, the elementary arsenic content in the above sex organs and plasma was comparable to the controls (Table 5
).
|
![]() |
DISCUSSION |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
The low plasma level of gonadotrophins in the group treated with arsenic alone corresponds with the quantitative findings of depressed folliculogenesis in this experiment. The decreased number of healthy follicles after arsenic treatment and the elevation in the number of apoptotic follicles in arsenic-treated rats have been attributed to low FSH levels (Gore-Langton and Daniel, 1990; Roy and Treacy, 1993
).
The decrease in peroxidase activity in the follicular fluid or the high concentration of superoxide radical may be one of the major factors that are responsible for follicular regression (Cassano et al., 1999; Paszkowski et al., 1995
). Peroxidase is one of the major components of the antioxidant system (Hochstein and Atallsh, 1988
; Sun, 1990
; Susa et al., 1996
). The low levels of peroxidase activity in ovarian tissue found in our study after sodium arsenite treatment support these data. The normal levels of these parameters after selenium supplementation may be due to the protection against arsenic-induced oxidative stress (Helzlsouer et al., 1996
). Exogenous administration of selenium was reported to have some stimulatory effect on ovarian peroxidase activity (Apostolski et al., 1998
). The pronounced reduction in elemental arsenic content in the reproductive organs and plasma after dietary intake of selenium may be due to the possibility of trapping arsenic, thereby resulting in a low uptake of arsenic in these organs. An inverse relationship between selenium and arsenic has been reported in the literature (Beckman and Nordenson, 1986
; Flora et al., 1999
; Rostkowska-Nadolska et al., 1999
).
Selenium may also act on the granulosa cells by modulating their proliferation and estradiol synthesis (Basini and Tamanini, 2000). The protection of folliculogenesis in our selenium-supplemented group also supports the recovery in ovarian steroidogenesis and normal functioning of the hypothalamohypophysialovarian axis. Selenium supplementation prevents the ovarian and uterine weight loss induced by arsenic, and this may be due to the rapid distribution of selenium to the ovary and uterus, which in turn may activate the selenium-dependent peroxidase activity (Sundstrom et al., 1989
), which is more pronounced in the ovary and uterus (Baiza-Gutman et al., 2000
; Sundstrom et al., 1989
).
Uterine tissue degeneration after arsenic treatment may result from decreased ovarian estradiol as uterine growth depends on the ovarian estradiol secretion (Patil et al., 1998). Moreover, there also may be a possibility of diminished progesterone action on estradiol-primed uterus, which may obstruct the transition of the uterine epithelium from the proliferative to the secretory state (Patil et al., 1998
). It has recently been established that uterine endometrium degeneration is associated with the increased production of reactive oxygen species such as superoxide radicals, hydrogen peroxide, and hydroxyl radicals (Beltran-Garcia et al., 2000
). This is supported by our findings of a significant decrease in uterine peroxidase activity after sodium arsenite treatment in this experiment.
Dietary administration of selenium ameliorates the inhibitory effect of sodium arsenite on the uterus and prevents a reduction in uterine size, endometrial and myometrial thickness, and height of epithelial layer. This protective effect may be the result of selenium preventing the decrease in estradiol level induced by arsenic alone, which in turn may be responsible for the normalization of uterine peroxidase activity (Farley et al., 1992; Wang and Qi, 1993
), as peroxidase activity is responsible for the maintenance of uterine sensitivity and receptivity (Baiza-Gutman et al., 2000
).
Since selenium is unable to prevent an elevation in the weight of the liver and to protect the arsenic-mediated changes in the activities of renal and hepatic acid phosphatase, alkaline phosphatase, and transaminases (such as GOT and GPT), it therefore may be stated that a preventive effect of selenium on arsenic-induced toxicity is specific for reproductive organs.
For the preventive action of selenium on arsenic-induced disorders in female reproductive system, the following two hypotheses may be formulated. One is that selenium may modulate the hypothalamicpituitaryovarian axis by the stimulation of dopaminergic or adrenergic neurons or by the inhibition of serotonergic neuronal activities and by its direct stimulatory effects on ovarian steroidogenesis that maintain ovarian folliculogenesis. An alternative hypothesis is that arsenic-induced reproductive toxicity may be due to the induction of oxidative stress or free radical generation, and, since selenium is an important dietary antioxidant, it may prevent this toxicity by its free radical scavenging action (Helzlsouer et al., 1996; Sreekala et al., 1999
). Further studies are needed to clarify the mechanism of selenium prevention of the arsenic-induced disorders in the female reproductive system.
![]() |
NOTES |
---|
![]() |
REFERENCES |
---|
![]() ![]() ![]() ![]() ![]() ![]() ![]() |
---|
Apostolski, S., Marinkovic, Z., Nikolic, A., Blagojevic, D., Spasic, M. B., and Michelson, A. M. (1998). Glutathione peroxidase in amyotrophic lateral sclerosis: The effects of selenium supplementation. J. Environ. Pathol. Toxicol. Oncol. 17, 325329.[Medline]
Basini, G., and Tamanini, C. (2000). Selenium stimulates estradiol production in bovine granulosa cells: Possible involvement of nitric oxide. Domest. Anim. Endocrinol. 18, 117.[CrossRef][ISI][Medline]
Baiza-Gutman, L. A., Flores-Sanchez, M. M., Diaz-Flores, M., and Hicks, J. J. (2000). Presence of uterine peroxidase activity in the rat early pregnancy. Int. J. Biochem. Cell Biol. 32, 255262.[CrossRef][ISI][Medline]
Baxley, M. N., Hood, R. D., Vedel, G. C., Harison, W. T., and Szczech, G. M. (1981). Prenatal toxicity of orally administered sodium arsenite in mice. Bull. Environ. Contam. Toxicol. 26, 749756.[ISI][Medline]
Beckman, L., and Nordenson, I. (1986). Interaction between some common genotoxic agents. Hum. Hered. 36, 397401.[ISI][Medline]
Beltran-Garcia, M. J., Espinosa, A., Herrera, N., Perez-Zapata, A. J., Beltran-Garcia, C., and Ogura, T. (2000). Formation of copper oxychloride and reactive oxygen species as causes of uterine injury during copper oxidation of Cu-IUD. Contraception 61, 99103.[CrossRef][ISI][Medline]
Bleau, G., Lemarbre, J., Faucher, G., Roberts, K. D., and Chapdelaine, A. (1984). Semen selenium and human fertility. Fertil. Steril. 42, 890894.[ISI][Medline]
Biswas, S., Talukder, G., and Sharma, A. (1999). Prevention of cytotoxic effects of arsenic by short-term dietary supplementation with selenium in mice in vivo. Mutat. Res. 441, 155160.[ISI][Medline]
Cassano, E., Tosto, L., Balestrieri, M., Zicarelli, L., and Abrescia, P. (1999). Antioxidant defense in the follicular fluid of water buffalo. Cell Physiol. Biochem. 9, 106116.[CrossRef][ISI][Medline]
Chappell, W. R., Beck, B. D., Brown, K. G., Chaney, R., Richard, C. C., Irgolic, K. J., and North, D. W. (1997). Inorganic arsenic: A need and an opportunity to improve risk assessment. Environ. Health Perspect. 105, 10601065.[ISI][Medline]
Chatterjee, A., Das, D., Mandal, B. K., Samanta, G., and Banerjee, P. (1995). The biggest arsenic calamity in the world. Analyst 120, 643650.[ISI]
Chattopadhyay, S., Ghosh, S., Chaki, S., Debnath, J., and Ghosh, D. (1999). Effect of sodium sodium arsenite on plasma levels of gonadotrophins and ovarian steroidogenesis in mature albino rats: Duration dependent response. J. Toxicol. Sci. 24, 425431.[Medline]
Chattopadhyay, S., Ghosh, S., Debnath, J., and Ghosh, D. (2001). Protection of sodium arsenite-induced ovarian toxicity by coadministration of L-ascorbate (vitamin C) in mature Wistar strain rat. Arch. Environ. Contam. Toxicol. 41, 8389.[CrossRef][ISI][Medline]
Chattopadhyay, S., Misro, M., Ghosh, S., Debnath, J., and Ghosh, D. (2000). Effect of -tocopherol succinate (vitamin E) on sodium arsenite induced ovarian steroidogenic function and plasma levels of gonadotrophins in mature albino rats. Tox. Sub. Mech. 19, 137150.[CrossRef]
Choudhury, S. A., Sharpe, R. M., and Brown, P. S. (1973). Pituitary follicle-stimulating hormone activity in rats treated with apomorphine, pimozide and drugs that modify catecholamine levels. Neuroendocrinology 12, 272283.[ISI][Medline]
Chowdhury, T. R., Mandal, B. K., Samanta, G., Basv, G. K., Chowdhury, P. P., Chanda, C. R., Karan, N. K., Lodh, D., Dhar, R. K., and Das, D. (1997). Arsenic in ground water in six districts of West Bengal, IndiaThe biggest arsenic calamity in the world: The status report up to August, 1995. In Arsenic Exposure and Health Effects (C. O. Abernathy, R. L. Calderson, and W. R. Chappell, Eds.), pp. 93111. Chapman and Hall, New York.
Christian, J. J. (1964). Actions of ACTH in intact and coticoid-maintained adrenalectomized female mice with emphasis on the reproductive tract. Endocrinology 75, 655657.
Clemens, J. A., Tinsley, F. C., and Fuller, R. W. (1977). Evidence for a dopaminergic component in the series of neural events that lead to the pro-oestrous surge of LH. Acta Endocrinol. (Copenh.) 85, 1824.[Medline]
Das, P. C., Pharikal, K., Dey, C. D., Mondal, R. K., and Dasgupta, S. (1990). Further evidence that catecholaminergic and serotonergic neurotransmitters of rat brain involved in modulation of gonadotrophin release. Ind. J. Physiol. All. Sci. 44, 3845.
Donald, M. C., Edwards, R. A., and Greenhalgh, J. F. D. (1995). Minerals. In Animal Nutrition (M. C. Donald, R. A. Edwards, and J. F. D. Greenhalgh, Eds.), pp. 127136. Longman ELBS, England.
Edman, C. D. (1983). The effect of steroid on endometrium. Semin. Reprod. Endocrinol. 1, 179187.[ISI]
Farley, D. B., Ford, S. P., and Rosazza, J. P. (1992). Increase in uterine peroxidase activity in the rat uterus during oestrogen hyperaemia. J. Reprod. Fertil. 95, 551558.[Abstract]
Flora, S. J., Kannan, G. M., and Kumar, P. (1999). Selenium effects on gallium arsenide induced biochemical and immunotoxicological changes in rats. Chem. Biol. Interact. 30(122), 113.
Flora, S. J. S., Dube, S. N., Arora, U., Kannan, G. M., Sukla, M. K., and Malhotra, P. R. (1995). Therapeutic potential of meso 2,3-dimercaptosuccinic acid or 2,3-dimercaptopropane 1-sulfonate in chronic arsenic intoxication in rats. Biometals 8, 111116.[ISI][Medline]
Ghosh, D., Chattopadhyay, S., and Debnath, J. (1999). Effect of sodium arsenite on adrenocortical activity in immature female rats: Evidence of dose dependent response. J. Environ. Sci. 11, 419422.
Goebl, H. H., Schmidt, P. F., Bohl, J., Teltenborn, B., Kramer, G., and Gutmann, L. (1990). Polyneuropathy due to arsenic intoxication: Biopsy studies. J. Neurol. 49, 137149.
Goel, B. K. (1988). Routine biochemical tests. In Medical Laboratory Technology (K. L. Mukherjee, Ed.), Vol. III, pp. 9851079. Tata McGraw-Hill, New Delhi.
Gore-Langton, R. E., and Daniel, S. A. (1990). Follicle-stimulating hormone and estradiol regulate antrum-like reorganization of granulosa cells in rat preantral follicle cultures. Biol. Reprod. 43, 6572.[Abstract]
Greenwood, F. O., Hunter, W. M., and Glover, J. S. (1963). The preparation of 131I labeled human growth hormone of high specific activity. Biochem. J. 89, 114123.[ISI]
Hanning, R., Oreyk, P. J., Caldwell, V. B., and Behrman, H. R. (1974). Estrogen and its radio-immunoassay. In Methods of Hormone Radio-immunoassay (B. M. Jaffe and H. R. Behrman, Eds.), pp. 675685. Academic Press, New York.
Helzlsouer, K. J., Alberg, A. J., Norkus, E. P., Morris, J. S., Hoffman, S. C., and Comstock, G. W. (1996). Prospective study of serum micronutrients and ovarian cancer. J. Natl. Cancer Inst. 88, 3237.
Hinshelwood, M. M., Demter-Arlotto, M., Means, G. D., and Simpson, E. R. (1994). Expression of genes encoding steroidogenic enzymes in the ovary. In Molecular Biology of the Female Reproductive System (J. K. Findlay, Ed.), pp. 129145. Academic Press, London.
Hochstein, P., and Atallsh, A. S. (1988). The nature of oxidants and anti-oxidants systems in the inhibition of mutation and cancer. Mutat. Res. 202, 363375.[ISI][Medline]
Hu, G., Liu, X., and Liu, J. (1996). Protective effects of sodium selenite and selenomethionine on genotoxicity to human peripheral lymphocytes induced by arsenic. Zhonghua Yu Fang Yi Xue Za Zhi 30, 2629.[Medline]
Hu, G. G. (1989). Investigation of protective effect of selenium on genetic materials among workers exposed to arsenic. Zhonghua Yu Fang Yi Xue Za Zhi 23, 286288.[Medline]
Imam, S. Z., and Ali, S. F. (2000). Selenium, an antioxidant, attenuates methamphetamine-induced dopaminergic toxicity and peroxynitrite generation. Brain Res. 855, 186191.[CrossRef][ISI][Medline]
Jarabak, J., Adams, J. A., Williams-Ashman, H. G., and Talalay, P. (1962). Purification of 17ß-hydroxysteroid dehydrogenase function. J. Biol. Chem. 237, 345357.
Kamel, F. A., and Kubajak, C. L. (1987). Modulation of gonadotropin secretion by corticosterone interaction with gonadal steroids and mechanism of action. Endocrinology 121, 561565.[Abstract]
Kato, K., Hayashi, H., Hasegawa, A., Yamanaka, K., and Okada, S. (1994). DNA damage induced in cultured human alveolar (L-32) cells by exposure to dimethylarsinic acid. Environ. Health Perspect. 102, 285288.[ISI][Medline]
Kaur, R., Dhanju, C. K., and Kaur, K. (1999). Effects of dietary selenium on biochemical composition of rat testis. Indian J. Exp. Biol. 37, 509511.[Medline]
Kent Shellenberger, M., and Gordon, J. H. (1971). A rapid, simplified procedure for simultaneous assay of norepinephrine, dopamine and 5-hydroxy-tryptamine from discrete brain areas. Anal. Biochem. 39, 356372.[ISI][Medline]
Klaassen, C. D. (1990). Heavy metals and heavy metal antagonists. In The Pharmaceutical Basis of Therapeutics (G. A. Goodman, T. W. Rall, A. S. Nies, and P. Taylor, Eds.), pp. 16021605. Pergamen Press, New York.
Kulin, H. E., and Reiter, E. O. (1973). Gonadotrophins during childhood and adolescene. A review. Pediatrics 51, 260271.[Abstract]
Lee, T. C., Oshimura, M., and, Barrett, J. C. (1985). Comparison of arsenic-induced cell transformation, cytotoxicity, mutation and cytogenetic effects in Syrian hamster embryo cells in culture. Carcinogenesis 6, 14211426.[Abstract]
Locke, J. (1979). The determination of eight elements in human liver tissue by flame atomic absorption spectrometry in sulfuric acid solution. Anal. Chem. Acta 104, 225231.[CrossRef]
Longnecker, M. P., and Daniels, J. L. (2001). Environmental contaminants as etiologic factors for diabetes. Environ. Health Perspect. 6(Suppl.), 871876.
Luton, J., Thiebott, P., Valcke, J., Mahendean, J. A., and Bricaire, H. (1977). Reversible gonadotropin deficiency in male Cushing disease. J. Clin. Endocrinol. Metab. 45, 488493.[Abstract]
Malymy, M., and Horecker, B. L. (1966). Alkaline phosphatase. In Methods of Enzymology, Vol. IX, pp. 639642. Academic Press, New York.
Mazumder, D. N., Guha, A., Chakraborty, A. K., and Ghosh, A. (1988). Chronic arsenic toxicity from drinking tube-well water in rural West Bengal. Bull. WHO 66, 499506.[ISI][Medline]
McCall, M. R., and Balz, F. (1999). Can antioxidant vitamins materially reduce oxidative damage in humans? Free Radic. Biol. Med. 26, 10341053.[CrossRef][ISI][Medline]
Moudgal, N. R., and Madhwa Raj, H. G. (1974). Pituitary gonadotrophin. In Methods of Hormone Radioimmunoassay (B. M. Jaffe and H. R. Behrman, Eds.), pp. 5785. Academic Press, New York.
Neiger, R. D., and Osweiler, G. D. (1989). Effect of subacute low level dietary sodium arsenite on dogs. Fundam. Appl. Toxicol. 13, 439451.[ISI][Medline]
Nickson, R., McArthur, J., Burges, W., Ahamed, K. M., Ravenserof, P., and Rahman, M. (1998). Arsenic poisoning of Bangladesh ground water. Nature 395, 338338.[CrossRef][ISI][Medline]
Nurenberg, W. H. (1982). Voltametric trace analysis in ecological chemistry of toxic metals. Pure Appl. Chem. 54, 853878.[ISI]
Odell, W. D., Swerdloff, R. S., Bain, J., Wallesen, F., and Grover, P. K. (1963). The effect of sexual maturation testicular response to LH stimulation of testosterone secretion in the intact rat. Endocrinology 72, 452464.[ISI]
Ogle, T. F. (1977). Modification of serum leuteinizing hormone and prolactin concentration by corticotropin and adrenalectomy in ovariectomized rats. Endocrinology 101, 494497.[Abstract]
Parshad, V. R., Kaur, P., and Guraya, S. S. (1989). Reproductive cycles of mammals. In Reproductive Cycles of Indian Vertebrates (S. K. Saidapur, Ed.), pp. 347408. Allied Publishers Ltd, Bombay.
Paszkowski, T., Traub, A. I., Robinson, S. Y., and McMaster, D. (1995). Selenium dependent glutathione peroxidase activity in human follicular fluid. Clin. Chem. Acta 236, 173180.[CrossRef][ISI][Medline]
Patil, S. R., Ravindra, Patil, S. R., Londonkar, R., and Patil, S. B. (1998). Nicotine induced ovarian and uterine changes in albino mice. Indian J. Physiol. Pharmacol. 42, 503508.[Medline]
Rahman, M. M., Mandal, B. K., Chowdhury, T. R., Sengupta, M. K., Chowdhury, U. K., Lodh, D., Chanda, C. R., Basu, G. K., Mukherjee, S. C., Saha, K. C., et al. (2003). Arsenic groundwater contamination and sufferings of people in North 24-Parganas, one of the nine arsenic affected districts of West Bengal, India. J. Environ. Sci. Health Part A Tox. Hazard Subst. Environ. Eng. 38, 2559[CrossRef][ISI][Medline]
Ringstrom, S. J., and Schwartz, N. B. (1985). Cortisol suppresses the LH release and ovulation in cyclic rat. Endocrinol. 116, 472475.[Abstract]
Rostkowska-Nadolska, B., Pospiech, L., and Bochnia, M. (1999). Content of trace elements in serum of patients with carcinoma of the larynx. Arch. Immunol. Ther. Exp. (Warsz) 47, 321325.
Roy, A. K. (1999). Chemistry of arsenic and arsenic minerals relevant to contamination of groundwater and soil from subterranean source. Everymans Science 34, 1521.
Roy, S. K., and Treacy, B. J. (1993). Isolation and long-term culture of human preantral follicles. Fertil. Steril. 59, 783790.[ISI][Medline]
Sadasivan, S., and Manickam, A. (1996). Peroxidase. In Methods in Biochemistry (S. Sadasivan and A. Manickam, Eds.), pp. 108110. New Age International Publishers, New Delhi.
Saha, A. K. (1991). Pollution in ground water in West Bengal: Final report, Steering Committee, Arsenic Investigation Project, PHE Dept., Government of West Bengal, pp. 156.
Saha, K. C. (1995). Chronic arsenical dermatosis from tube-well water in West Bengal during 198387. Indian J. Dermatol. 40, 112.
Sarkar, M., Biswas, N. M., and Ghosh, D. (1991). Effect of sodium arsenite on testicular 5-3ß, 17ß-HSD activities in albino rats: Dose and duration dependent responses. Med. Sci. Res. 19, 789790.
Skalnaia, M. G., Zhavoronkov, A. A., and Skalnyi, A. V. (1995). Morphologic characteristics of the thymus in pregnant and new born mice. Arkhiv Patologii 57, 5258.
Sreekala, M., Santosh, T. R., and Lalitha, K. (1999). Oxidative stress during selenium deficiency in seedlings of Trigonella foenum-graecum and mitigation by mimosine. Part I. Hydroperoxide metabolism. Biol. Trace. Elem. Res. 70, 193207.[ISI][Medline]
Sukla, J. P., and Pandey, K. (1984). Impaired spermatogenesis in arsenic-treated fresh water fish Colisa fasciatus (Bl and Sch). Toxicol. Lett. 21, 191195.[CrossRef][ISI][Medline]
Sun, Y. (1990). Free radicals, antioxidant enzymes, and carcinogenesis. Free Radic. Biol. Med. 8, 583599.[CrossRef][ISI][Medline]
Sundstrom, H., Korpela, H., Sajanti, E., and Kauppila, A. (1989). Supplementation with selenium, vitamin E and their combination in gynaecological cancer during cytotoxic chemotherapy. Carcinogenesis 10, 273278.[Abstract]
Susa, S., Ueno, S., Furukawa, Y., and Sugiyama, M. (1996). Protective effect of vitamin E on chromium (VI)-induced cytotoxicity and lipid peroxidation in primary cultures of rat hepatocytes. Arch. Toxicol. 71, 2024.[CrossRef][ISI][Medline]
Tabacova, S., Hunter, E. S., and Balabaeva, L. (1992). Potential role of oxidative damage in developmental toxicity of arsenic. In Arsenic: Exposure and Health Effects (C. O. Abernathy, R. L. Calderon, and W. R. Chappell, Eds.), pp. 135144. Chapman and Hall, London.
Tagatz, G. E., Fialkow, P. J., and Smith, D. (1970). Hypogonadotropic hypogonadism associated with anosmia in the female. N. Engl. J. Med. 283, 13261329.[ISI][Medline]
Taketani, S., Kohno, H., Tokunaga, R., Ishii, T., and Bannai, S. (1991). Selenium antagonizes the induction of human heme oxygenase by arsenite and cadmium ions. Biochem. Int. 23, 625632.[ISI][Medline]
Talalay, P. (1962). Hydroxysteroid dehydrogenase. In Methods in Enzymology (S. P. Colowick and N. O. Kaplan, Eds.), pp. 512516. Academic Press, New York.
Tseng, C. H., Tseng, C. P., Chiou, H. Y., Hsueh, Y. M., Chong, C. K., and Chen, C. J. (2002). Epidemiologic evidence of diabetogenic effect of arsenic. Toxicol. Lett. 133, 6976.[CrossRef][ISI][Medline]
Tsunoda, M., Johnson, V. J., and Sharma, R. P. (2000). Increase in dopamine metabolites in murine striatum after oral exposure to inorganic but not organic form of selenium. Arch. Environ. Contam. Toxicol. 39, 3237.[CrossRef][ISI][Medline]
Vanha-Perttula, T., and Nikkanen, V. (1973). Acid phosphatases of the rat testis in experimental conditions. Acta Endocrinol. 72, 376390.[ISI][Medline]
Vijayan, E., and McCann, S. M. (1978). Re-evaluation of the role of catecholamines in control of gonadotropin and prolactin release. Neuroendocrinology 25, 150165.[ISI][Medline]
Waalkes, M. P., Ward, J. M., Liu, J., and Diwan, B. A (2003). Transplacental carcinogenicity of inorganic arsenic in the drinking water: induction of hepatic, ovarian, pulmonary, and adrenal tumors in mice. Toxicol. Appl. Pharmacol. 186, 717.[CrossRef][ISI][Medline]
Wang, C. Y., and Qi, X. M. (1993). Studies on some trace elements and cell-mediated immunity in patients with gestational trophoblastic disease. J. Tongji. Med. Univ. 13, 5155.[Medline]
Yamanaka, K., Hoshino, M., Okamoto, M., Sawamura, R., Hasegawa, A., and Okada, S. (1990). Induction of DNA damage by dimethylarsine, a metabolite of inorganic arsenics, is for the major part likely due to its peroxyl radical. Biochem. Res. Commun. 168, 5864.[ISI]
Yang, C. Y., Chang, C. C., Tsai, S. S., Chuang, H. Y., Ho, C. K., and Wu, T. N. (2003). Arsenic in drinking water and adverse pregnancy outcome in an arseniasis-endemic area in northeastern Taiwan. Environ. Res. 91, 2934.[CrossRef][ISI][Medline]
Zar, J. H. (1996). One sample hypothesis. In Biostatistical Analysis (J. H. Zar, Ed.), pp. 9398. Prentice Hall, Englewood Cliffs, NJ.
Zadorozhnaja, T. D., Little, R. E., Miller, R. K., Mendel, N. A., Taylor, R. J., Presley, B. J., and Gladen, B. C. (2000). Concentrations of arsenic, cadmium, copper, lead, mercury, and zinc in human placentas from two cities in Ukraine. J. Toxicol. Environ. Health A 61, 255263.[CrossRef][ISI][Medline]
|