SIGNIFICANCE OF OPIOID, CANNABINOID, BRADYKININ RECEPTORS AND КАТP-CHANNELS IN THE CARDIOPROTECTIVE EFFECT OF ADAPTATION TO COLD

Abstract

HighlightsIt has been shown that chronic adaptation to cold (28 days, +2 – +4°C) has a cardioprotective effect in in vivo model of myocardial ischemia/reperfusion injury in rats. Certain types of receptors and КАТP-channels might be involved in mechanisms of this effect. Aim. To evaluate the role of opioid, cannabinoid, bradykinin receptors and the КАТP-channels in the infarct-limiting effect of chronic adaptation to cold.Methods. The study involved male Wistar rats weighing 250–300 g. Rats (two in a cage) were placed in a refrigerator for 28 days. The temperature inside the chamber was +2 – +4oC. The infarct-limiting effect of chronic adaptation to cold and its possible cancelation by receptor blockers was studied in a 45-minute coronary artery occlusion and a 120-minute reperfusion of the rat myocardium in vivo. The quantitative assessment of myocardial injury was determined by the necrotic zone to the area at risk (NZ/AAR) ratio.Results. We have found that КАТP-channels are involved in the mechanism of the infarct-limiting effect of chronic adaptation to cold. Opioid, cannabinoid and bradykinin receptors are not involved in this effect.Conclusion. The obtained results have expanded our understanding of cold adaptation, as well as receptor pathways involved in the mechanism of ischemia/reperfusion injury resistance. Further studying of the signaling and receptor pathways of the infarct-limiting effect of cold adaptation will reveal molecules responsible for tolerance to ischemia/reperfusion injury. These molecules can be used to develop novel cardioprotective drugs for the treatment of acute myocardial infarction.