Conversion of 11-ketoandrostenedione to 11-ketotestosterone by Blood Cells of Six Fish Species

Blood cells from Baltic salmon, Salmo salar, three-spined stickleback, Gasterosteus aculeatus, eel pout, Zoarces viviparus, crucian carp, Carassius carassius, African catfish, Clarias gariepinus, and reedfish, Calamoichthys calabaricus, were incubated with tritiated 11 beta-hydroxyandrostenedione (OHA) or 11-ketoandrostenedione (OA). In all fish there was conversion of OA to 11-ketotestosterone (OT), indicating that 17 beta-hydroxysteroid dehydrogenase activity was present in the blood cells. On the other hand, OHA was not converted to 11 beta-hydroxytestosterone in any fish. The addition of serum to the incubates largely prevented the OA-OT conversion by salmon blood cells.