Effect of metoclopramide, domperidone and apomorphine on GH secretion in children and adolescents

Abstract

The way in which the dopaminergic system controls GH secretion in infancy and adolescence was investigated by studying the effects on GH of a specific dopaminergic agonist apomorphine, and two antagonists, metoclopramide (MC), which can and domperidone (DOM), which cannot cross the blood-brain-barrier, (BBB), in 14 males and 6 females aged 8-17 years. Treatment with both antagonists was followed by a marked increase in Prl, whereas only MC stimulated GH secretion, suggesting that this action must occur inside the BBB if it is linked to antidopaminergic properties. GH secretion was also stimulated by apomorphine, which acts at the central level. The paradox posed by the presence of a central effect on GH secretion derived from both an agonist and an antagonist of the dopaminergic receptors is discussed.