On the catecholamine control of growth hormone regulation. Evidence for discrete changes in dopamine and noradrenaline turnover following growth hormone administration

Abstract

Two hours following treatment with rat growth hormone (100 μg/kg, i.v.) a reduction of noradrenaline (NA) levels in the rat's hypothalamic subependymal layer was observed. Further findings indicate a reduction of dopamine (DA) turnover in the medial and lateral palisade zone of the median eminence and of NA turnover in the posterior perinventicular hypothalamic region. This suggests thee existence of a facilitory noradrenergic mechanism in the posterior periventricular hypothalamic region facilitating growth hormone secretion and that of an inhibitory dopaminergic mechanism in the medial palisade zone inhibiting the secretion of somatostatin.