اثر پيش درماني به نورآدرنالين و نقش گيرنده a1 آدرنرژيكي و كانال پتاسيمي وابسته به ATP ميتوكندريايي بر آنزيم هاي قلبي پلاسما در مدل ايسكمي / پرفيوژن مجدد قلب موش صحرايي بيهوش

Effect of pretreatment by noradrenaline and role of at adrenoceptor and mitochondrial ATP sensitive potassium channel on cardiac enzymes in ischemiaJreperfused heart in anesthetized rat

AIMS. Noradrenaline protects myocardium against ischcmia/reperfusion-induced infarction and arrhythmias via activation of c-udrenoceptor and mitochondrial K,\Tp channels (mKAT P) in anesthetized rats. In present study we evaluated the effect of noradrenaline and role of c.cadrenoccpror and mKATP channel on plasma level of Lactate dehydrogenase (LDH) and Creatine kinase-MB (CKMB) . l\1ETHODS. Anesthetized rats were subjected to 25 minutes regional ischaemia and 120 minutes reperfusion. In control group (n=9) saline was injected prior to ischemia. In [PC group (Ischemic Preconditioning: n=9) ischemia was preceded by three short episodes of ischemia/reperfusion. In group III (n=9). noradrenaline (2 ugr/kg) was injected prior to ischemia. In group IV (n=6), an (,{\-adrenoceptor blocker (prazosin, 0.5 rug/kg) was administrated prior to noradrenaline. In Groups V and VI In=6). rats received 5-hydroxydecanoiate (5-HD; a specific mK"TP channel inhibitor) prior to and after noradrenaline injection. respectively. RESULTS. IPC and noradrenaline markedly reduced plasma level of LDH and CKMB. Administration of prazosin or 5-HD suppressed effect of noradrenaline on LDH and CKMH• CONCLUSION. Noradrenaline reduces plasma level of LDH and CKMB via activation of u.-udrenoceptor and mitochondrial KATP channel in anesthetized rat heart.