Glutamergic action on alpha-melanocyte-stimulating hormone release from the rat hypothalamus.
Release of alpha-melanocyte-stimulating hormone (alpha-MSH) synthesized in the hypothalamus is regulated by monoaminergic neuronal systems. An endogenous dopaminergic system inhibits alpha-MSH release (1, 2) whilst serotoninergic systems exert a biphasic effect on peptide release (3). The toxic effects of neonatal peripheral administration of monosodium glutamate on hypothalamic neurons containing proopiomelanocortin- (POMC-) derived peptides (4, 5) suggest additionally the presence of glutamate receptors on or indirectly influencing the POMC neuron. By comparison of the effect of the excitatory amino-acid agonists N-methyl-D-aspartate (NMDA), quisqualate and kainate on the release of alpha-MSH from superfused slices of rat hypothalamus, we have demonstrated a stimulatory glutamergic action on alpha-MSH release mediated through NMDA-type receptors.
Tiligada
E
E
Department of Pharmacology and Therapeutics, University of Wales College of Medicine, Heath Park, Cardiff CF4 4XN, UK.
Wilson
J F
JF