Identification of 5 alpha-dihydrotestosterone in avian plasma

Conscious adult domestic mallard drakes were intravenously injected with tritiated testosterone. After 30 min of in vivo conversion the steroids were extracted from the plasma and submitted to thin-layer chromatography (TLC). Using radiogas chromatography, labeled 5 alpha-dihydrotestosterone (5 alpha-DHT), androsterone, and epiandrosterone could be identified in the androstanolone fraction. 5 alpha-DHT was separated in a second TLC system and definitively identified by recrystallization to constant specific activity.