Hexarelin exhibits protective activity against cardiac ischaemia in hearts from growth hormone-deficient rats

Male rats were treated with growth hormone (GH)-releasing hormone antiserum to induce selective GH deficiency. The chronic administration of hexarelin to these GH-deficient rats had a pronounced protective effect against ischaemic and post-ischaemic ventricular dysfunction. Hexarelin prevented hyper-responsiveness of the coronary vascular bed to angiotensin 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 acts via stimulation of specific cardiac and vascular receptors, triggering currently unknown cytoprotective mechanisms that are responsible for resistance to ischaemic insults and for the preservation of the integrity of the endothelial vasodilation function.