Role of the hypothalamic opioidergic system in the control of gonadotropin secretion in elderly men

The role of opioidergic system in controlling gonadotropin secretion in elderly men still remains uncertain. In the present study, we attempted to examine the opioidergic inhibitory tone imposed on GnRH release mechanism in elderly men by monitoring the plasma gonadotropin response to the opiate receptor antagonist naloxone hydrochloride. Six normal young men and 10 elderly men with no endocrinological diseases volunteered for the present study. In young men, plasma LH showed a biphasic increase in response to naloxone and plasma LH level during naloxone treatment was significantly higher than the mean of prenaloxone control levels. In contrast, plasma LH in elderly men was not affected by naloxone