Cellular Observations and Hormonal Correlates of Feedback Control of Luteinizing Hormone Secretion by Testosterone in Long-Term Castrated Male Rhesus Monkeys1

Testosterone at physiological levels cannot exert negative feedback action on LH secretion in long-term castrated male monkeys. The cellular basis of this refractoriness is unknown. To study it, we compared two groups of male rhesus macaques: one group (group 1, n = 4) was castrated and immediately treated with testosterone for 30 days; the second group (group 2, n = 4) was castrated and treated with testosterone for 9 days beginning 21 days...