Lack of endogenous opioid inhibitory tone on LH secretion in early puberty

Thirteen normal children, seven males and six females, during early puberty (I-II according to Tanner), have been studied. Each subject was injected at weekly intervals and in random order with 100 micrograms of LHRH, 0.2 mg/kg of naloxone and 0.9% saline in single bolus. The gonadotrophin response was evaluated. The administration of naloxone failed to elevate LH levels in any of the subjects studied, even in those who showed a clear gonadotrophin response to LHRH. Unlike the response noted in adults, endogenous opiates do not appear to exert a tonic inhibitory influence on LH secretion during early puberty.