EFFECTS OF INHIBITORS OF CATECHOLAMINE SYNTHESIS AND CATECHOLAMINE AGONISTS ON MORPHINE- AND HYPOGLYCAEMIA-INDUCED RELEASE OF GROWTH HORMONE IN THE RAT

Abstract

Unité de Neuroendocrinologie, INSERM, U.159, 2 ter Rue d'Alesia, 75014 Paris, France (Received 16 August 1977) It is known that catecholamines play an important role in the regulation of growth hormone (GH) secretion, but the effects of dopamine and alpha- and beta-adrenergic agonists on the release of GH in the rat are controversial (Collu, Fraschini, Visconti & Martini, 1972; Kato, Dupre & Beck, 1973; Durand, Martin & Brazeau, 1977). It has been proposed (Bluet-Pajot, Schaub & Nassiet, 1976; Bluet-Pajot & Schaub, 1977; Durand et al. 1977) that the conflicting data obtained in the rat may be due to the anaesthesia; most of the GH responses reported to be atypical in the rat, compared with those of primates, were obtained under urethane anaesthesia, which is known to result in long-lasting and irreversible endocrine imbalance. In contrast, neurotransmitters or experimental hypoglycaemia do not appear to induce paradoxical GH responses in rats treated