Prostacyclin and iloprost: equal efficiency in preserving high energy phosphates in the dog heart following coronary artery ligation.

The influence of PGI2 and iloprost on the contents of high energy phosphates, cAMP, glycolytic metabolites and on cardiac performance was investigated in open-chest dogs subjected to 3 h of ischaemia, induced by occlusion of the left anterior descending coronary artery. The administration of drugs for 2 h, starting 1 h after the onset of ischaemia, resulted in a normalization and an appreciable reduction in the loss of high energy phosphates in the non-ischaemic and ischaemic left ventricular muscle, respectively, leading to an improvement in the phosphate potential of the cardiac tissue. A reduction in the ischemia-induced rise in cAMP levels was observed, indicating a lower catecholamine overflow in the presence of these drugs. PGI2 and iloprost in the dose employed significantly decreased cardiac preload, which was found to be elevated in the untreated animals after coronary artery ligation. The observed effect of PGI2 and its mimetic on the haemodynamics, as well as on myocardial cAMP and high energy phosphate levels of the heart, may be considered helpful in the phase of temporary imbalance between energy demand and supply during acute ischaemia.