Role of cyclooxygenase-2 and mitochondrial KATP channels in sufentanil preconditioning-induced delayed cardioprotection against myocardial ischemia-reperfusion injury in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the role of cyclooxygenase-2(COX-2)and mitochondrial adenosine tuiphosphate sensitive potassium channels (mito-KATP channels) in sufentanil preconditioning-induced delayed cardiopreteetion against myocardial ischemia-reperfnsion (I/R) injury in rats. Methods Seventy-two adult male Wistsr rats weighing 250-300 g were randomly divided into 6 groups ( n =12 each). Group Ⅰ,Ⅱ,Ⅲ were preconditioned with intraperitoneal (IP) normal saline (NS) 1 ml/kg while group Ⅳ,Ⅴ,Ⅵ with IP sufentanil 20 μg/kg at 24 h before myocardial ischemia. Group Ⅱ and Ⅴ were given IP NS-398 ( COX-2 inhibitor) 5 mg/kg at 30 rain before myocardial ischemla while group Ⅲ and Ⅵ were given intravenous 5-HD (mito-KATP channelblocker) 10 mg/kg at 10 min before ischemia or before being killed. Six animals in each group underwent 45 min myocardial ischemia followed by 120 min reperfusion, while the other six animals in each group were killed immediately before ischemia for determination of myocardial COX-2 expression and myocardial PGF2 and PGF1α content. Myocardial ischemia was induced by occlusion of left anterior descending branch (LAD) of coronary artety for 45 rain followed by 120 min reperfusion. MAP and HR were recorded immediately before ischemia (T0), at 15, 30, 45 rain of ischemia (T1-3) and at 30, 60, 90, 120 vain of reperfusion (T4-7). Heart rate-blood pressure product (RPP) was calculated. Arterial blood samples were obtained at T0.3 and T7 for measurement of plasma CK-MB activity. The animals were killed at the end of 120 nan reperfusion. The hearts were removed for determination of myocardial infarct area (IA) and area at risk (AAR). LA/AAR was calculated. Results There was no significant difference in HR, MAP and RPP at all time points among the 6 groups. Preconditioning with sufentanil significantly decreased plasma CK-MB activity at T3 and T7 and IA/AAR in group Ⅳ as compared with group Ⅰ.Myocardial COX-2 expression was up-regulated and PGE2 and PGF1α, contents were elevated by sufentanil preconditioning in group Ⅳ as eomared with control group (Ⅰ). In group Ⅴ and Ⅳ preconditioning with NS-398/5-HD significantly increased plasma CK-MB concentration and IS/AAB as compared with group Ⅳ, indicating involvement of COX-2 and mito-KATP channels in the sufentanil-induced delayed cardioprotection.The myocardial PGE2 and PGF1α contents were significantly reduced in group Ⅴ as compared with group Ⅳ. There was no significant difference in the myocardial COX-2 expression among group Ⅳ, Ⅴ and Ⅵ. Conclusion Both COX-2 and mito-KATP channels are involved in sufentanil preconditioning-induced delayed cardiopmtection.