Metabolism of androstenedione and 11-ketotestosterone in the kidney of the three-spined stickleback, Gasterosteus aculeatus

Abstract

Stickleback kidneys were incubated with tritiated androstenedione (A4) or 11-ketotestosterone (OT). After the A4 incubations the following steroids were found, testosterone (T), 5 beta-androstane-3,17-dione (5 beta Ad), etiocholanolone (Et), 5 beta-dihydrotestosterone (5 beta DHT), 5 beta-androstane-3 alpha,17 beta-diol (5 beta A3 alpha 17 beta diol), androsterone, 5 alpha-androstane-3,17-dione, 5 alpha-androstane-3 alpha,17 beta-diol (5 alpha A3 alpha 17 beta diol), as well as glucuronides of T, Et, 5 beta DHT, 5 beta A3 alpha 17 beta diol, and 5 alpha A3 alpha 17 beta diol. The metabolites found in the largest amounts were usually T, 5 beta Ad, Et, and the glucuronides of T, Et, and especially of 5 beta A3 alpha 17 beta diol. These results suggest the main pathway to be A4-5 beta Ad-Et-5 beta A3 alpha 17 beta diol-5 beta A3 alpha 17 beta diol-glucuronide or Et-Et-glucuronide-5 beta A3 alpha 17 beta diol-glucuronide. The formation of 5 beta-reduced compounds was larger in postbreeding males and females than in breeding males. The opposite was the case for 5 alpha-reduced compounds. The total formation of glucuronides was lower in the breeding males than in the other groups. After the OT incubations 11-ketoandrostenedione, 17 beta-hydroxy-5 beta-androstane-3,11-dione (tentatively identified), and OT-glucuronide were found. 17 beta-Hydroxy-5 alpha-androstane-3,11-dione was not present.