endogenous androgens ( androstenedione , testosterone , 5 alpha-dihydrotestosterone and 5 alpha-androstane-3 alpha,17 beta-diol ) , and some of their c21 precursors ( pregnenolone , progesterone and 17-hydroxyprogesterone ) were measured in rat testes between day 18.5 of pregnancy and day 64 postpartum , and correlated with numerical densities of leydig cells .
C0033308
progesterone
C0020387
17-hydroxyprogesterone