P. Sreenivasula Reddy

Exposure to high fluoride concentration in drinking water will affect spermatogenesis and steroidogenesis in male albino rats.

Sodium fluoride (NaF) administered orally to adult male rats at a dose level of 4.5 ppm and 9.0 ppm for 75 days caused significant decrease in the body weight, brain index and testicular index. A significant decrease in sperm count, sperm motility, sperm viability and sperm function (HOS positive) with increased sperm abnormalities was also observed in NaF-exposed male rats. The activity levels of testicular steroidogenic marker enzymes 3β-hydroxysteroid dehydrogenase (3β-HSD) and 17β-hydroxysteroid dehydrogenase (17β-HSD) were significantly decreased in NaF-treated rats indicating decreased steroidogenesis and in turn spermatogenesis in rats exposed to NaF.

Protective effects of N-acetylcysteine against arsenic-induced oxidative stress and reprotoxicity in male mice

Arsenic is a well-known environmental toxic metalloid element and carcinogen that affects multiple organ systems including tissue lipid peroxidation and reproduction. The present study was aimed to investigate the protective role of N-acetylcysteine (NAC) on arsenic-induced testicular oxidative damage and antioxidant and steroidogeneic enzymes and sperm parameters in mice. Arsenic was administered through drinking water to mice at a concentration of 4.0 ppm sodium arsenite (actual concentration 2.3 ppm arsenic) for 35 days. The body weight of treated mice did not show significant change as compared with the control mice. In arsenic exposed mice there was a significant decrease in the weight of the testis, epididymis and prostate gland as compared with the control animals. Significant reduction was observed in epididymal sperm count, motile sperms and viable sperms in mice exposed to arsenic indicate decreased spermatogenesis and poor sperm quality. The activity levels of testicular 3β- and 17β-hydroxysteroid dehydrogenases and circulatory levels of testosterone were also decreased in arsenic treated mice indicating reduced steroidogenesis. A significant increase in the activities of lipid peroxidation and a significant decrease in the activities of antioxidant enzymes were observed in the testis of mice exposed to arsenic. In addition, significant increase in the testicular arsenic levels was observed during arsenic intoxication. No significant changes in the oxidation status and selected reproductive variables were observed in the N-acetylcysteine alone treated mice. Whereas, intra-peritoneal injection of NAC to arsenic exposed mice showed a significant increase in the weights of reproductive organs, reduction in arsenic-induced oxidative stress in the tissues and improvement in steroidogenesis over arsenic-exposed mice indicating the beneficial role of N-acetylcysteine to counteract arsenic-induced oxidative stress and to restore the suppressed reproduction in male mice.

INVOLVEMENT OF METHYL FARNESOATE IN THE REGULATION OF MOLTING AND REPRODUCTION IN THE FRESHWATER CRAB OZIOTELPHUSA SENEX SENEX

Abstract The influence of methyl farnesoate (MF) in the regulation of molt and gonad development in the crab Oziotelphusa senex senex was investigated. Injection of methyl farnesoate into female and male crabs significantly (P < 0.0001) increased mean oocyte diameter (236.37%) and testicular follicle diameter (25.72%) as well as mean gonad indices (females 1304.35%; males 38.00%) and also accelerated the molting (females 80%; males 100%). These results provide strong evidence that methyl farnesoate is involved in the control of both molting and reproduction in crabs.

Effect of restraint stress on lead-induced male reproductive toxicity in rats.

This study was undertaken to investigate whether chronic immobilization stress interferes with lead-induced reproductive toxicity in rats. Early pubertal male Wistar rats were subjected to either restraint stress (5 hr/day) or maintained on lead (0.15%) containing water or both for 60 days. Restraint stress or lead treatment significantly decreased the weight of the testes and epididymis. The daily sperm production, epididymal sperm count, sperm motility, and sperm viability were also decreased after exposure to lead or subjected to restraint stress. The levels of serum testosterone and also activity levels of testicular hydroxysteroid dehydrogenases were significantly decreased with a significant increase in the serum follicle stimulating and luteinizing hormone levels in rats exposed to lead or restraint stress indicating decreased steroidogenesis. A significant increase in lipid peroxidation levels and decrease in catalase and superoxide dismutase activity levels were observed in the testes of rats subjected to restraint stress or exposed to lead indicating increased oxidative stress. Extensive histopathological malformations were observed in the testis of the treated rats. From the findings, the study suggests that restraint stress or exposure to lead affects male reproduction in rats by inducing oxidative stress followed by decreasing steroidogenesis and spermatogenesis. A significant decrease in spermatogenesis and steroidogenesis was also observed in rats subjected to both restraint stress and lead treatment as compared to lead alone treated rats indicating immobilization stress augments lead-induced testicular and epididymal toxicity in rats.

Protective role of Centella asiatica on lead-induced oxidative stress and suppressed reproductive health in male rats

Centella asiatica has been mentioned in ancient ayurvedic text of the Indian system of medicine for its properties to promote intelligence. The objective of the present study was to investigate the beneficial effects of C. asiatica on lead-induced oxidative stress and suppressed reproductive performance in male rats. Significant decrease in the weights of testes and epididymis were observed in lead treated animals. Exposure to lead acetate significantly increased malondialdehyde levels with a significant decrease in the superoxide dismutase and catalase activities in the liver, brain, kidneys and testes of rats. Epididymal sperm count, viable sperms, motile sperms and HOS-tail coiled sperms decreased significantly in lead-exposed rats. Testicular steroidogenic enzyme activities also decreased significantly in lead-exposed rats. No significant changes in the selected reproductive variables were observed in the plant extract alone treated rats. Whereas, co-administration of aqueous extracts of C. asiatica to lead exposed rats showed a significant increase in the weights of reproductive organs, reduction in lead-induced oxidative stress in the tissues and improvement in selected reproductive parameters over lead-exposed rats indicating the beneficial role of C. asiatica to counteract lead-induced oxidative stress and to restore the suppressed reproduction in male rats.

Lead acetate induced reproductive and paternal mediated developmental toxicity in rats

Lead was administered orally to adult male rats at exposure level of 273 or 819 mg/L (0.05% or 0.15% lead acetate, respectively) for 45 days via drinking water. At the end of the exposure period, control and experimental males were mated with untreated females. Of the females mated with treated males, 73.3% in the 0.05% group and 53.33% in the 0.15% group showed copulatory plugs. Significant decrease in number of implantations and pre- and post-implantation loss was also observed in females mated with treated males. Significant decrease in the weight of the reproductive organs, reduction in epididymal sperm count, motile sperm and viable sperm were observed in lead-exposed rats indicating decreased sperm production and deteriorated sperm quality. Significant decrease in serum testosterone levels were also observed in treated rats indicating decreased steroidogenesis. The decreased serum testosterone levels and deteriorated sperm quality might be responsible for the suppressed reproduction in rats after exposure to lead.

In vitro methyl farnesoate secretion by mandibular organs isolated from different molt and reproductive stages of the crab Oziotelphusa senex senex

Considerable evidences indicate that mandibular organ (MO) of crustaceans secrete terpenoid hormone (methyl farnesoate [MF]), which regulates molting and reproduction. In the freshwater south Indian rice field crab Oziotelphusa senex senex, MO isolated during premolt and vitellogenesis, secreted greater amounts of MF, which indicates that the regulation of the crustacean molt and reproduction is complex and also involves MF, besides steroid (ecdysteroid) and peptide (sinus gland peptide) hormones.

Mandibular organ: it's relation to body weight, sex, molt and reproduction in the crab, Oziotelphusa senex senex Fabricius (1791)

The dynamics of the mandibular organ (MO) in the edible fresh water field crab Oziotelphusa senex senex was studied as a function of sex, weight, reproduction, molting and eyestalk ablation (ESX). The weight of the mandibular organ exhibited a positive correlation with the body weight. In general, male crabs possess larger mandibular organs when compared to female crabs. The weight of the mandibular organ increased with ovarian index, molting and as the crab progressed towards reproduction. Bilateral eyestalk ablation resulted in a significant increase in mandibular organ weight. The methyl farnesoate (MF) content of the mandibular organ increased with increase in organ weight. The results presented strongly support a potential role of the mandibular organ in regulating both molting and reproduction.

Reproductive Endocrinology of Female Crustaceans: Perspective and Prospective

Reproduction in crustaceans is a highly complex process that requires precise coordination of external and internal factors to be successful. The field of crustacean reproductive endocrinology has moved from the classical approach of endocrinological techniques such as extirpation and additive methods, to the modern era of advanced biochemical, immunological, molecular biology and recombinant DNA technology methods. During last two decades, extensive endeavor has been captivating on the crustacean endocrines regulating reproduction, to authenticate their roles in the regulation of reproduction as well as their biochemical and molecular mechanism of action. In the present chapter, we have tried to recapitulate recent developments in molecular advances taken place in the reproduction regulation of crustacea via hormones, opioids, neurotransmitters and other molecules. In addition to providing a review of the scientific literature, we have also included our perspectives.

Aflatoxin B1-Induced Reproductive Toxicity in Male Rats Possible Mechanism of Action

Aflatoxin B1 (AFB1), one of the most common mycotoxins found in human foods, is principally hepatotoxic; however, it also affects reproduction. The aim of the present study was to elucidate the reproductive toxic effects and possible mechanism of action of AFB1 in rats. Male Wistar rats were injected intramuscularly with doses of 10, 20, or 50 µg AFB1/kg body weight on alternate days from 45 to 100 days of age. Significant reductions in body weights, relative weights of reproductive organs, daily sperm production, epididymal sperm count, viable sperm, motile sperm, and hypoosmotic swelling-tail coiled sperm were observed. Significant decreases in testicular steroidogenic enzymes and serum testosterone levels were also observed indicating decreased steroidogenesis. In silico docking studies illustrated AFB1 binds with steroidogenic acute regulatory (StAR) protein thereby affecting the transport of cholesterol into mitochondria resulting in decreased steroidogenesis.