Androgens modulate testicular androgen production in African catfish (Clarias gariepinus) depending on the stage of maturity and type of androgen.

摘要: Previous work showed that androgen treatment suppressed testicular steroidogenesis in juvenile African catfish Clarias gariepinus. Similar to other vertebrates, however, circulating levels increase during puberty catfish. We therefore studied if androgen-induced inhibition of production decreases sexual maturation. As testosterone (T) is found the circulation fish but typically, 11-ketotestosterone (11-KT) quantitatively dominating androgen. In previous studies with catfish, these two androgens different biological activities as regards spermatogenesis or pituitary hormone production, were equally effective suppressing steroidogenesis. Hence, second question we was types show distinct effects on steroidogenic system pubertal adult males. The inhibitory effect 11-KT capacity waned progressing maturation, while T-mediated remained strong until adulthood reducing vitro steroid 4- 10-fold. However, gonadotropin responsiveness tissue not compromised and expression receptors did respond differently androgens. conclude selective disappearance contributes allowing plasma level this