Effect of pretreatment with dexmedetomidine alone or in combination with sufentanil on myocardial ischemia-reperfusion injury in rats / 中华麻醉学杂志

ABSTRACT

Objective To investigate the effect of pretreatment with dexmedetomidine alone or in combination with sufentanil on myocardial ischemia-reperfusion (I/R) injury in rats.Methods Fifty healthy male Sprague-Dawley rats,weighing 250-300 g,were anesthetized with intraperitoneal pentobarbital sodium 60 mg/kg.Myocardial I/R was induced by occlusion of anterior descending branch of left coronary artery for 30 min followed by 120 min of reperfusion.The rats were then randomly divided into 5 groups (n =10 each)sham operation group (group S),group I/R,dexmedetomidine pretreatment group (group DP),sufentanil pretreatment group (group SP),and dexmedetomidine + sufentanil pretreatment group (group DS).In group S the anterior descending branch was only exposed but not ligated.Dexmedetomidine 0.5μg/kg and sufentanil 0.1μg/kg were injected intraperitoneally 30 min before ischemia in groups DP and SP,respectively.Dexmedetomidine 0.5 μg/kg and sufentanil 0.1 μg/kg were injected intraperitoneally 30 min bbefore ischemia in group DS.Arterial blood samples were collected at 120 min of reperfusion for determination of serum creatine kinase (CK) and lactic dehydrogenase (LDH)concentrations.The rats were sacrificed at 120 min of reperfusion and hearts were removed for microscopic examination.Myocardial infarct size was calculated.The malondialdehyde (MDA) content and superoxide dismutase (SOD) activity in myocardial tissues were measured.Results Compared with group S,the serum CK and LDH concentrations were significantly increased,the myocardial infarct size was enlarged,and SOD activity was decreased in the other groups,MDA content was significantly increased in groups I/R,DP and SP (P ＜ 0.05 or 0.01).Compared with group I/R,the serum CK and LDH concentrations,MDA content and myocardial infarct size were significantly decreased,and SOD activity was increased in groups DP,SP and DS (P ＜ 0.05).Compared with group DS,the serum CK concentration was significantly increased,the myocardial infarct size was enlarged,and MDA content was increased in groups DP and SP,and LDH concentration was significantly increased and SOD activity was decreased in group DP (P ＜ 0.05).The pathological changes were significantly attenuated in groups DP and SP compared with group DS.Conclusion Dexmedetomidine pretreatment can reduce myocardial I/ R injury in rats,dexmedetomidine combined with sufentanil pretreatment provides better efficacy than either alone,and inhibition of lipid peroxidation is involved in the mechanism.