title: The biosynthesis of 11-ketotestosterone by the testis of the Siamese fighting fish Betta splendens Regan (Anabantoidei, Belontiidae).
abstract: Testicular tissues of the Siamese fighting fish were incubated with [14C]pregnenolone for 10, 20, 30, 50, 80, and 120 min, and with [14C]progesterone, [14C]11 beta-hydroxyandrostenedione, [14C]11 beta-hydroxytestosterone, and [14C]androstenetrione for 120 min. 11-Ketotestosterone was the main metabolite in all 120-min incubations. No 11-oxygenated C21 steroids were found as metabolites of either pregnenolone or progesterone. The biosynthesis of 11-ketotestosterone proceeded through both the delta 5- and the delta 4- pathways as judged from the shape of the yield-time curves of the metabolites of pregnenolone. 11-Ketotestosterone formation from 11-oxygenated precursors increased in the order 11 beta-hydroxytestosterone less than 11 beta-hydroxyandrostenedione less than androstenetrione.
mesh_terms: D000735:Androstenedione / Q000031:analogs & derivatives / Q000378:metabolism; D000818:Animals; D005399:Fishes / Q000378:metabolism*; D006915:Hydroxytestosterones / Q000378:metabolism; D007700:Kinetics; D008297:Male; D011284:Pregnenolone / Q000378:metabolism; D011374:Progesterone / Q000378:metabolism; D013737:Testis / Q000378:metabolism; D013739:Testosterone / Q000031:analogs & derivatives* / Q000096:biosynthesis
chemical_list: D006915:Hydroxytestosterones; C037914:11-hydroxytestosterone; D013739:Testosterone; D000735:Androstenedione; D011374:Progesterone; C003582:11-hydroxyandrostenedione; D011284:Pregnenolone; C003600:11-ketotestosterone