RESUMEN
We analyzed the role of opioid receptors in the conditioning effect of continuous normobaric hypoxia on bioenergetics of the heart subjected to ischemia/reperfusion injury. Male Wistar rats were adapted to a 21-day continuous normobaric hypoxia (12% pO2). Then, the hearts were isolated and subjected to 45-min total ischemia followed by 30-min reperfusion. Damage to the myocardium was assessed by activity of creatine phosphokinase in the perfusate. Experiments on isolated mitochondria showed that ischemia/reperfusion injury decreased the respiration rate in state 3 (V3), the ratio of added ADP and oxygen consumption in respiration state 3 (ADP/O ratio), the mitochondrial potential across the inner membrane (Δψ), and Ca2+ binding capacity of mitochondria. In addition, ischemia/reperfusion injury decreased myocardial ATP. Preventive continuous normobaric hypoxia pronouncedly moderated these adverse effects of reperfusion. It was found that its protective effects were related to activation of cardiac µ- and δ2-opioid receptors.
Asunto(s)
Metabolismo Energético/fisiología , Hipoxia/metabolismo , Mitocondrias Cardíacas/metabolismo , Daño por Reperfusión Miocárdica/metabolismo , Receptores Opioides/fisiología , Adaptación Fisiológica/efectos de los fármacos , Adaptación Fisiológica/fisiología , Animales , Compuestos de Bencilideno/farmacología , Metabolismo Energético/efectos de los fármacos , Corazón/efectos de los fármacos , Masculino , Mitocondrias Cardíacas/efectos de los fármacos , Miocardio/metabolismo , Naltrexona/análogos & derivados , Naltrexona/farmacología , Antagonistas de Narcóticos/farmacología , Consumo de Oxígeno/efectos de los fármacos , Consumo de Oxígeno/fisiología , Ratas , Ratas WistarRESUMEN
The course of treatment with combined adaptogenic plant preparation Tonizid improved mouse survival under conditions of hypobaric hypoxia and reduced the necrotic zone/risk zone ratio during ischemia and reperfusion in rats under conditions of artificial ventilation. The test preparation decreased the size of the necrotic zone, but had no effect on the size of the risk zone. Tonizid prevented ventricular fibrillation during coronary occlusion and exhibited antihypoxic, cardioprotective, and antifibrillation properties.