Aromatase, estrogen 2-hydroxylase, and catechol-O-methyltransferase activity in isolated, cultured gonadotropic cells of mature African catfish, Clarias gariepinus (Burchell).

Isolated gonadotropic cells were able to convert androstenedione into estrone. Subsequently, estrone could be metabolized via catecholestrone into 2-methoxyestrone. From these results it can be concluded that the gonadotropes of mature catfish contain the enzymes aromatase, estrogen 2-hydroxylase, and catechol-O-methyltransferase. The possible function of these enzymes in the steroid negative feedback regulation of gonadotropic hormone release is discussed.