NEUROTRANSMITTER CONTROL OF GROWTH-HORMONE SECRETION IN HUMANS

Growth hormone secretion is mainly regulated by the interplay of GHRH and somatostatin, two specific hypophysiotrophic neurohormones. In add ition to GHRH and somatostatin, many neurotransmitters and neuropeptid es influence GH secretion mainly by acting at the hypothalamic level. This paper focuses on the stimulatory role of acetylcholine, arginine and galanin as well as on the inhibitory influence of catecholamines w hich is mediated by the activation of beta-adrenergic receptors. Atten tion will be given to the age-related changes in the neural control of GH secretion from childhood to old age.