Assay of perinatal testosterone and influence of anti-progesterone and theophylline on induction of sterility

Mean serum levels of testosterone (T) determined by radioimmunoassay were found to be reliably higher in male than female rats at 21 days of gestation and 6 hr and 3 days after birth. However, serum T concentrations in individual female samples were frequently equal to or greater than those found in male samples. Another study was performed to evaluate whether protection against androgen in females might be associated with mechanisms involving circulating progesterone and cellular adenosine 3′5′-cyclic monophosphate (cAMP). Female rats were injected on the day of birth with 1.0 μg testosterone propionate (TP) or sesame oil in combination with theophylline, antiserum to progesterone or saline. Females injected with TP lost vaginal cyclicity. The duration of time after puberty before reaching the sterility criterion was approximately 86% and 35% shorter for TP-groups receiving theophylline and antiprogesterone, respectively, than for those injected with saline. Thus, progesterone might provide some protection against the defeminizing effects of T and cAMP could be involved in hormone action during the perinatal period.