Ontogeny of rodent testicular androgen production in response to isoproterenol and luteinizing hormone in vitro.

The ontogeny of rodent testicular androgen production in response to the catecholamine agonist L-isoproterenol (Isop) and luteinizing hormone (LH) was studied in vitro. Isop (10(-4) M) significantly increased rat androgen production by 1.2- 3.3-fold on Days 18.5 to 21.5 of gestation and on Days 1 to 60 of postnatal life during the 3-h incubation in Medium 199. Similarly, Isop augmented mouse androgen production by 1.4- to 4.3-fold on Days 16.5 to 19.5 of gestation and on 1, 10, 20 40 and 60 days of postnatal life. No effect of the beta-agonist was observed in postnatal rats aged 6 and 10 days, and mice aged 2, 5, 15 and 30 days. In both species, LH (100 ng/ml) induced large increases (2.8- to 265.6-fold) in androgen production at all fetal and postnatal ages. Isop was 0.3-22.9% as effective as LH in the two species. The minimum concentration of Isop to significantly increase androgen production by testes from 20.5-day rat fetuses was 10(-8) M, while 10(-5) M was required to stimulate 17.5-day mouse fetuses. Isop significantly increased androgen production by 20.5-day rat and 17.5-day mouse fetuses after a time lag of 30 and 180 min, respectively. In both species, a beta-adrenergic antagonist, propranolol (10(-5) M), abolished the increased androgen production attributed to Isop. Propranolol alone and the D-isomer of Isop had no effect. The results indicate that although LH is the key stimulant of testicular androgen production, catecholamines may play an important role(s) in testicular development, especially at fetal ages.