Rajkumar Maiti

Testicular toxicity in sodium fluoride treated rats: association with oxidative stress.

This study examined the effect of sodium fluoride, a water pollutant important through the world, including India, on testicular steroidogenic and gametogenic activities in relation to testicular oxidative stress in rats. Sodium fluoride treatment at 20mg/kg/day for 29 days by oral gavage resulted in significant diminution in the relative wet weight of the testis, prostate, and seminal vesicle without alteration in the body weight gain. Testicular delta(5),3beta-hydroxysteroid dehydrogenase (HSD) and 17beta-HSD activities were decreased significantly along with significant diminution in plasma levels of testosterone in the fluoride-exposed group compared to the control. Epididymal sperm count was decreased significantly in the fluoride-treated group and qualitative examination of testicular sections revealed fewer mature luminal spermatozoa in comparison to the control. The seminiferous tubules were dilated in treated animals. Fluoride treatment was associated with oxidative stress as indicated by an increased level of conjugated dienes in the testis, epididymis, and epididymal sperm pellet with respect to control. Peroxidase and catalase activities in the sperm pellet were decreased significantly in comparison to the control. The results of this experiment indicate that fluoride at a dose encountered in drinking water in contaminated areas exerts an adverse effect on the male reproductive system and this effect is associated with indicators of oxidative stress.

Effect of human chorionic gonadotrophin coadministration on ovarian steroidogenic and folliculogenic activities in cyclophosphamide treated albino rats

Quantitative evaluation of ovarian Delta5,3beta- hydroxysteroid dehydrogenese (HSD) and 17beta - HSD activities along with radioimmunoassay of plasma levels of gonadotrophins (FSH and LH), and estradiol (E2), and quantification of different types of developing follicles and regressive follicles were noted in mature rats of the Wistar strain following treatment with cyclophosphamide at a dose of 5 mg/kg body weight/day for 28 days. A significant reduction in plasma levels of LH and E2 along with significant diminution in the activities of ovarian Delta5,3beta -HSD and 17beta- HSD were observed following cyclophosphamide treatment for 28 days without any change in the plasma level of FSH. This treatment also produced a marked degree of degeneration in different types of follicles. Coadministration of hCG at 5 IU/kg body weight/day for 28 days in the cyclophosphamide-treated group provided significant protection except with respect to plasma LH. These results suggest the possibility of an indirect action of cyclophosphamide at the level of the ovary.

Fluoride-Induced Immunotoxicity in Adult Male Albino Rat: A Correlative Approach to Oxidative Stress

Fluoride pollution in drinking water is an international problem as the fluoride present is often at levels above acceptable limits. In the studies reported here, sodium fluoride (NaF) treatment of rats by gavage for 28 days resulted in the induction of oxidative stress and immunotoxicity. It was shown here that NaF treatment lowered cellular immunity in the rats as illustrated by a significant diminution in peripheral blood lymphocyte, monocyte and neutrophil counts in conjunction with a reduction in splenocyte counts. Effects of NaF treatment on humoral immunity were reflected here in a lowering of the levels of plasma IgG specific to a test antigen (i.e., bovine serum albumin). Disorganization in the histoarchitecture was also noted in the host spleen and thymus after NaF treatment. To determine if oxidative stress was among the potential possible causes for the observed induced immunotoxicities, catalase and peroxidase activities along with malondialdehyde (MDA, product of free radical damage to cells) levels in the spleen and peripheral blood packed cells were also measured. The results indicated that there was a significant diminution in the activities of both the enzymes along with an elevation in MDA levels in both the tissues in treated rats. This report highlights the proposition that chronic exposure to fluoride contaminated drinking water is likely to result in immunotoxicity and, furthermore, that the damage to primary immune organs is due to an induction of oxidative stress.

Effect of human chorionic gonadotrophin coadministration on the activities of ovarian Δ5-3β-hydroxysteroid dehydrogenase, and 17β-hydroxysteroid dehydrogenase, and ovarian and uterine histology in lithium chloride-treated albino rats

Lithium chloride, a compound with clinical use in bipolar disorder, produces adverse effects on ovarian function in amphibian and rodent models. This study examined the effect of human chorionic gonadotrophin coadministration on ovarian steroidogenic and gametogenic activities in lithium chloride-treated rats. Relative ovarian and uterine weights, ovarian Delta(5)-3beta-hydroxysteroid dehydrogenase and 17beta-hydroxysteroid dehydrogenase activities, folliculogenesis, uterine diameter, endometrial and myometrial thickness, and uterine luminal epithelial height were decreased significantly after lithium chloride treatment for 28 days at 1.6 mg/kg/day, the human therapeutic dose. These parameters were unchanged from the control level when subcutaneous (s.c.) human chorionic gonadotrophin (hCG) at 25 microg/kg/day was coadministered with the lithium chloride. The duration of the oestrous cycle was increased in lithium chloride-treated rat with longer metestrous and diestrous phases. Administration of hCG with lithium chloride prevented these estrous cycle alterations. We conclude that hCG can protect ovarian steroidogenic and gametogenic function after lithium chloride treatment.

Induction of Oxidative Stress on Reproductive and Metabolic Organs in Sodium Fluoride-Treated Male Albino Rats: Protective Effect of Testosterone and Vitamin E Coadministration

The present study was undertaken to search out the effect of sodium fluoride, a water pollutant noted throughout the world, including India, on oxidative stress induction in reproductive tissues, sperm pellet, and metabolic tissues like the liver and kidney. The protective effects of testosterone or vitamin-E coadministration were also observed on oxidative stress in the above mentioned samples. A significant diminution was noted in the activities of catalase and peroxidase, important antioxidant enzymes in testicular tissue, sperm pellet, prostate, and epididymis in sodium fluoride-treated rats at the dose of 20 mg/kg body weight/day (the level noted in drinking water in fluoride intoxicated areas) for 30 days by oral gavage. Coadministration of testosterone by intraperitoneal injection at the dose of 40 μg/100 g body weight/alternate day, 3 hours after fluoride treatment, resulted in a significant protection in the above mentioned parameters of all these samples. Moreover, fluoride treatment also resulted a significant elevation in the level of malondialdehyde and conjugated dienes, indicators of oxidative stress, in all the above mentioned samples, which were resettled toward the control level after testosterone coadministration. Testiculo-somatic, prostato-somatic, and epididymo-somatic indices were decreased significantly in the fluoride-treated group when compared to the vehicle-treated control group. Testosterone coadministration resulted in significant restoration of these indices to the control level. We also measured the above parameters for the evaluation of oxidative stress in the liver and kidney, important metabolic organs, and noted that there was also a significant elevation in malondialdehyde and conjugated dienes along with diminution in catalase and peroxidase activities in the fluoride treated-group, with respect to the vehicle treated control group. Testosterone coadministration resulted a significant protection in these parameters toward the vehicle-treated control level. There was no significant change in hepato-somatic and reno-somatic indices among fluoride-treated, testosterone coadministered, and vehicle-treated rats. Body weight of the animals among these three groups were not changed significantly. To find out the antioxidative property of testosterone compared to vitamin E, one group of fluoride-treated animals were subjected to coadministration of vitamin E at the dose of 20 mg/100 g body weight. It was noted that in reproductive organs and in metabolic organs, oxidative stress parameters were recovered toward the control level. The results of our experiment suggests that fluoride at the dose noted in drinking water in contaminated areas may induce oxidative stress in reproductive and metabolic organs that can be ameliorated significantly by testosterone or vitamin E coadministration. Moreover, as there was no significant variation in body weights among these groups, it may be predicted that this effect of fluoride on reproductive and metabolic organs is specific and is not due to general effect of fluoride.