Characterization of testicular expression of P450 17α-hydroxylase, 17,20-lyase in zebrafish and its perturbation by the pharmaceutical fungicide clotrimazole

The aim of the present study was to characterize P450 17α-hydroxylase/17,20-lyase (cyp17a1) expression in zebrafish and to assess the effect of the pharmaceutical clotrimazole, a known inhibitor of various cytochrome P450 enzyme activities, on testicular gene and protein expression of this enzyme as well as on the testicular release of 11-ketotestosterone (11-KT), a potent androgen in fish. We first showed that cyp17a1 is predominantly expressed in gonads of zebrafish, notably in male. In vivo, clotrimazole induced a concentration-dependent increase of cyp17a1 gene expression and Cyp17-I protein synthesis in zebrafish testis. Using zebrafish testicular explants, we further showed that clotrimazole did not directly affect cyp17a1 expression but that it did inhibit 11-KT release. These novel data deserve further studies on the effect of azole fungicides on gonadal steroidogenesis.

► Cyp17-I enzyme was immunolocalized within the gonadal tissue in zebrafish.
► In vivo, clotrimazole increased cyp17a1 gene and protein expressions in testis.
► In testis explants, clotrimazole inhibited 11-ketotestosterone release.
► Clotrimazole affects differently testicular steroidogenesis in vivo and ex vivo.