Toxic Effect Of Quail Testis Mediated By Nuclear Receptor Exposure To Atrazine

Atrazine(ATR) was the most widely used organophosphate pesticides in agricultural production throughout the world highly. ATR contaminates the aquatic environment by agriculture runoff and irrigation waters. ATR has damage to various organisms because of accumulation and transfer through the food chain. In recent years, because of widespread use, long retention period, high detection rate and toxicology action on animals, ATR was paid highly attention. However, the effects of ATR on birds were rarely investigated and there is a big controversy with the results. In order to better understand and analysis it, in this paper, we studied the effects of ATR on reproductive toxicity. In total, the quails were divided into four groups, and each group was treated with a specific concentration of ATR(50, 250 and 500mg/kg) by oral for 45 ds. Antioxidant level, organizational structure, biochemical analysis, six hormones, CYP450 activities and gene expression(CYPs, nuclear receptor and regulating key factors of testicular steroid hormones in Hypothalamic- pituitary- testicular axis), protein Expression of CYP11A1 and CYP17A1 were determined. The results showed that:1. ATR exposure reduced weight gain and relative weight of testis. ATR were seriously impacted on organizational structure and ultrastructure of quail live. These histopathological changes provided a morphological basis after exposure to ATR.2. ATR exposure can induce ROS production in the testes, depressed the activities of GST and GSH-PX, and induce the content of GSH and then the body’s antioxidant defense system was destructed which caused testicular tissue damage and affect the normal physiological functions.3. Here, we detected P450 activities and the mRNA levels of CYPs in quail testes. The results showed that ATR exposure could affect the content of CYP450 activities and the expression of CYPs. ATR could regulated the expressions of nuclear receptors such as CAR, AHR and PXR to induce the expression of CYPs subtype genes.4. The test results of six sex hormones indicated that ATR could lead to disorders of sex hormones. Gene expressions of hormones in the hypothalamic-pituitary-gonadal axis(HPGs) were disturbed by ATR. On the other hand, ATR blocked synthetic pathway of testosterone through reduced protein expression of CYP11A1 and CYP17A1.In conclusion, ATR exposure could cause testicular damage, induce CYP450 enzyme activities and mRNA expressions of CYPs subtype. ATR could interference regulation function of gonadal axis, disorder sex hormone and produce serious toxic effects to reproductive system of quail.