Participation of calcium ions in the molecular mechanism of cardioprotective action of exogenous phosphocreatine

Abstract

The purpose of this study was to find out whether Ca2+ is necessary for the protective effect of phosphocreatine (PCr) on ischemic myocardium. Isolated Langendorff-perfused rat hearts were used in the study. When ischemic arrest was induced in Ca(2+)-free buffer, PCr did not exert a protective effect on ischemic myocardium. PCr improved postischemic contractile recovery of hearts subjected to ischemia in perfusion media containing 0.5 and 1.2 mmol/l Ca2+. Phosphoarginine, a structural analogue of PCr which possesses Ca(2+)-binding property similar to that of PCr did not exert any protective effect on ischemic myocardium. The effects of PCr and Ca2+ on lipid order of sarcolemmal vesicles from canine heart were studied by using ESR spectroscopy. PCr made membrane phospholipids more tightly packed at mildly acidic and neutral pH, but did not at pH 8.5. Although Ca2+ itself did not influence the membrane structure at pH 5.5, it potentiated the effect of PCr on sarcolemmal phospholipids. Thus, the protective effect of PCr on ischemic myocardium is not attributed to its Ca2+ binding properly, but Ca2+ is a necessary component of the mechanism of protective effect of PCr on ischemic myocardium.

Effects of high‐energy phosphates on carbachol‐evoked cationic current in single smooth muscle cells from guinea‐pig ileum.

“…An anti-arrhythmic effect of PCr has also been shown (Rozenshtraukh, Witt, Nance & Rozanski, 1990;). An effect of PCr has been shown on liposomal and erythrocyte membranes and on the sarcolemmal membrane of cardiomyocytes (Konorev et al 1991). PCr and ATP were shown to be important for a rapid functional response to catecholamine stimulation of the heart (Kupriianov et al 1991) and for thyroid control of the heart (Seppet et al 1991).…”

“…PCr has a cardioprotective effect on ischaemic myocardium, accelerating postischaemic restoration of the contractility of the heart (Konorev, Medvedeva, Jalilashvili, Lakomkin & Saks, 1991;Kryzhanovskii, Kacharava, Marko, Kelemen, Kaverina & Saks, 1991). An anti-arrhythmic effect of PCr has also been shown (Rozenshtraukh, Witt, Nance & Rozanski, 1990;).…”

Nutritional Interventions as Potential Strategy to Minimize Exercise-Induced Muscle Injuries in Sports

“…Considering that high-force eccentric exercise alters myofibre membrane structure and function [9,141] leading to reductions in force, increased soreness, and impaired muscle function and that membrane stabilization due to decreased membrane fluidity is followed to increased intracellular concentration of phosphocreatine [142], the effects of creatine supplementation on markers of eccentric exercise damage have been assessed following resistance exercise sessions [143][144][145][146]. Initial studies conducted in rodents and humans agreed to demonstrate that creatine supplementation does not decrease muscle damage or enhance recovery after high intensity eccentric contractions.…”