HEXARELIN EXHIBITS PROTECTIVE ACTIVITY AGAINST CARDIAC ISCHEMIA IN HEARTS FROM GROWTH HORMONE-DEFICIENT RATS

Male rats were treated with growth hormone (GH)-releasing hormone anti serum to induce selective GH deficiency. The chronic administration of hexarelin to these GH-deficient rats had a pronounced protective effe ct against ischaemic and post-ischaemic ventricular dysfunction. Hexar elin prevented hyper-responsiveness of the coronary vascular bed to an giotensin II and also prevented the reduction in generation of 6-keto- prostaglandin F-1 alpha in perfused hearts from GH-deficient rats. The most plausible interpretation of these findings is that hexarelin act s via stimulation of specific cardiac and vascular receptors, triggeri ng currently unknown cytoprotective mechanisms that are responsible fo r resistance to ischaemic insults and for the preservation of the inte grity of the endothelial vasodilation function.