Sexual maturation in male rhesus monkeys: Importance of neonatal testosterone exposure and social

In a 5-year longitudinal study, we examined the eVect of disrupting the neonatal activity of the pituitary–testicular axis on the sexual development of male rhesus monkeys. Animals in a social group under natural lighting conditions were treated with a GnRH antagonist (antide), antide and androgen, or both vehicles, from birth until 4 months of age. In antide-treated neonates, serum LH and testosterone were near or below the limits of detection throughout the neonatal period. Antide+androgen-treated neonates had subnormal serum LH, but above normal testosterone concentrations during the treatment period. From 6 to 36 months of age, serum LH and testosterone were near or below the limits of detection. Ten of 12 control animals reached puberty during the breeding season of their 4t