Bodicharla Narayana » Публикация

Аннотация Deterioration of male reproductive health is one of the rising problems in the recent past. Recently there has been increased awareness of the possible effects of environmental pollutants on male reproduction (Sharpe, 1993; Becker and Berhane, 1997). Many reproductive malformations including retention of nipples, abnormal sexual behavior, birth defects, decreased spermatogenesis, reduced gonad weights and sub-fertility/infertility have been reported in laboratory animals and wildlife exposed to endocrine disrupting chemicals and in humans, impaired fertility, declining sperm count and quality, and undescended testes also have been attributed to exposure to environmental contaminants (Toppari et al., 1996). It has been reported that many pollutants act as endocrine disrupting chemicals and capable of affecting all most all compartments of hormonally-regulating functions including reproduction. It is assumed that endocrine disrupting chemicals affect the male reproductive health, by mimicking or antagonizing endogenous hormones, modifying hormone receptor levels, and/or altering the synthesis and metabolism of endogenous hormones. Endocrine disruptors may affect mammalian development either indirectly or directly, by altering the development and differentiation of target tissues including reproductive and accessory reproductive organs. It is believed that, reproductive disorders are thought to originate in developing stages of the fetus’s life in the womb and continue to occur throughout the reproduction. Exposure to xenobiotics during early stages of life is of particular concern since embryos are highly sensitive to alterations in hormones. Hormones play many critical roles in controlling growth and development in early life, such that any interference will have a serious and irreversible effect on the child. The increase in the incidence of certain conditions of the reproductive system has revealed a parallel rise in the manufacture and use of chemicals and such chemicals are known as ‘reproductive toxicants’. Vinclozolin (3-(3-5-dichlorophenyl)-5-methyl-oxazolidine-2,4-dione) is a systemic dicarboximide fungicide used to control the fungus by inhibiting the spore germination on several fruits, vegetables, ornamental plants and turf grass in golf courses and wine industry (Kelce et al., 1994). Nevertheless, the restrictions implemented over the last few decades have resulted in the current situation where contaminating sources, particularly those from industrial activities in developed countries, are very limited. Vinclozolin acts as a reproductive toxicant. Vinclozolin affects male reproduction in mammals by blocking the binding of androgen to its receptor. Chronic exposure to low doses of vinclozolin is known to cause reproductive impairments including behavioral changes in men (Flynn et al., 2001). Exposure to vinclozolin results in decreased sperm quantity and quality and suppressed fertility in adult rats (Eustache et al., 2009). Although a large number of studies have been reported on detrimental and deleterious effects of vinclozolin on reproduction, the reproductive toxic effects of vinclozolin during neonatal period has not attracted the interest of researchers. A few toxicological studies have addressed the possible relationship between reproductive toxicity and exposure to vinclozolin but the results are controversial and the effect of vinclozolin on male-mediated developmental toxicity is still unclear. The present research has been undertaken to evaluate the effect of vinclozolin on male reproductive health in rats exposed during neonatal period and/or during pubertal period. This study deals with the effect of vinclozolin on growth and feed intake, sperm density and quality, activity levels of steroidogenic marker enzymes, serum hormones, testicular oxidative status, activity levels of antioxidant enzymes, architecture of testis, reproductive performance and first generation developmental landmarks of male rats. The dissertation presents a humble effort by the researcher towards a better understanding of the effect of vinclozolin for further studies on male reproduction. The researcher assumes the responsibility for any deficiencies presented in the text, which could be due to oversight, and earnestly request condemnation.