Protective effect of pretreatment with the calcium antagonist anipamil on the ischemic-reperfused rat myocardium: A phosphorus-31 nuclear magnetic resonance study

• Published in: Journal of the American College of Cardiology Vol. 11; no. 5; pp. 1087 - 1093
• Main Authors: Kirkels, J.Hans, Ruigrok, Tom J.C, Van Echteld, Cees J.A, Meijler, Frits L
• Format: Journal Article
• Language: English
• Published: New York, NY Elsevier Inc 01.05.1988; Elsevier Science
• Subjects: Animals; Antianginal agents. Coronary vasodilator agents; Biological and medical sciences; Calcium Channel Blockers - administration & dosage; Calcium Channel Blockers - pharmacology; Calcium Channel Blockers - therapeutic use; Cardiovascular system; Coronary Circulation - drug effects; Coronary Disease - prevention & control; Hydrogen-Ion Concentration; Injections, Intraperitoneal; Intracellular Fluid - metabolism; Magnetic Resonance Spectroscopy; Male; Medical sciences; Myocardial Contraction - drug effects; Myocardium - metabolism; Pharmacology. Drug treatments; Phosphorus Radioisotopes; Premedication; Propylamines - administration & dosage; Propylamines - pharmacology; Propylamines - therapeutic use; Rats; Rats, Inbred Strains; Intraperitoneal administration; Rat; Rodentia; Cardiovascular disease; NMR spectrometry; Coronary heart disease; Isolated organ; Prevention; Vertebrata; Chemotherapy; Experimental disease; Mammalia; Reperfusion; Animal; Pretreatment
• ISSN: 0735-1097; 1558-3597
• DOI: 10.1016/S0735-1097(98)90069-9

To assess whether the prophylactic administration of anipamil, a new calcium antagonist, protects the heart against the effects of ischemia and reperfusion, rats were injected intraperitoneally twice daily for 5 days with 5 mg/kg body weight of this drug. The heart was then isolated and perfused by the Langendorff technique. Phosphorus-31 nuclear magnetic resonance spectroscopy was used to monitor myocardial energy metabolism and intracellular pH during control perfusion and 30 min of total ischemia (37 °C), followed by 30 min of reperfusion. Pretreatment with anipamil altered neither left ventricular developed pressure under normoxic conditions nor the rate and extent of depletion of adenosine triphosphate (ATP) and creatine phosphate during ischemia. Intracellular acidification, however, was attenuated. On reperfusion, hearts from anipamil-pretreated animals recovered significantly better than untreated hearts with respect to replenishment of ATP and creatine phosphate stores, restitution of low levels of intracellular inorganic phosphate and recovery of left ventricular function and coronary flow. Intracellular pH recovered rapidly to preischemic levels, whereas in untreated hearts a complex intracellular inorganic phosphate peak indicated the existence of areas of different pH within the myocardium. It is concluded that anipamil pretreatment protects the heart against some of the deleterious effects of ischemia and reperfusion. Because this protection occurred in the absence of a negative inotropic effect during normoxia, it cannot be attributed to an energy-sparing effect during ischemia. Therefore, alternative mechanisms of action are to be considered.