Effect of Cypermethrin on conjugation of sex steroid hormones during reproductively active and reproductively inactive phases of the annual reproductive cycle in Heteropneustes fossilis (Bloch)

The aim of the present investigation was to assess the impact of cypermethrin exposure for 40 days at sublethal concentration (0.02 ppm) on gonado-somatic index (GSI) and the conjugation of plasma levels of free and conjugate reproductive sex steroids- testosterone (T), 11-ketotestosterone (11-KT), 17 hydroxyprogesterone (17-P) and 11-deoxycortisol (S) during prespawning and post-spawning phases of the annual reproductive cycle in freshwater male catfish, Heteronpneustes fossilis. Results indicate that there is decrease in conjugation (glucuronide and sulfate) after exposure. Histology of testes indicates gross condensation of spermatogenic cells, cytotoxic damage and vacuolization in the tubular epithelium in the testes after exposure. Cypermethrin causes inhibition of free to conjugate form of sex steroids. Obviously such changes and inhibition of free to its glucuronide and sulfate sex steroids causes the disturbances in the equilibrium of sex hormones and affects the pheromonal behavior and reproduction by these conjugates of this species.