Short-term exposure of enrofloxacin inhibits synthesis of central estradiol through secretoneurin a/aromatase B (cyp19a1b) pathway in crucian carp.

Abstract

It has been reported that enrofloxacin (ENR) disrupts metabolic pathway of steroid in female crucian carp, promoting testosterone (T) synthesis through stimulating expression of luteinizing hormone (LH) and inhibiting conversion of T to estradiol (E₂) through repressing aromatase A expression. To further learn effect of ENR on steroid metabolism in fish, this work investigated effect of ENR on central E₂ synthesis and the involved mechanisms in female crucian carp through evaluating contents of T and E₂ in blood and brain, expression of secretogranin 2a (scg2a), gonadotrophin 2 β (gth 2β, namely LH) and aromatase B (cyp19a1b) genes in brain, and activation of PI3K/Akt pathway in brain of ENR exposed female crucian carp. Results revealed that ENR promoted steroid metabolism in brain of female crucian carp, stimulated synthesis of T synthesis but inhibited conversion of T to E₂ through promoting expression of scg2a and gth 2β but repressing expression of cyp19a1b, PI3K/Akt signaling pathway participated in regulating the biological process.