In Vitro effects of Cadmium Chloride on Steroid Profiles of Post-Vitellogenic Ovary in the Catfish Heteropneustes Fossilis

Cadmium (Cd) is a known endocrine disruptor with the ability to affect the production of hormones involved in the regulation of reproductive processes. The purpose of this study was to evaluate invitro effects of cadmium chloride (CdCl2) exposure on steroid levels in post-vitellogenic follicles of catfish ovary. Pieces of ovarian tissues (500mg) were incubated in culture medium in the presence or absence (control) of CdCl2 (0,0.01,0.1,1,3 and 10μg/ml) for 12 or 24hr. Estradiol-17 (E2) and testosterone were measured by ELISA. Other steroids like progestins (progesterone -P4; 17-OH-progesterone -17- P and 17,20 -dihydroxyprogesterone -17,20 -DP) and corticosteroids (cortisol, 21-deoxycortisol, corticosterone and deoxycorticosterone) were quantified by High Performance Liquid Chromatography. The results show that Cd produced biphasic effects on E2, T, P4, 17,20 -DP, cortisol, deoxycorticosterone, and 21-deoxycortisol, stimulatory at lower concentrations and inhibitory at higher concentrations. In contrast, 17-P and corticosterone were inhibited in a dose-dependent manner. Thus, Cd can influence ovarian steroidogenesis adversely, affecting gametogenesis and ovulation resulting in the decline of fish population.