Effects of propofol on cell apoptosis during myocardial ischemia-reperfusion in rats with type 2 diabetes mellitus

Objective To investigate the effects of propofol on cell apoptosis during myocardial ischemiareperfusion (I/R) in rats with type 2 diabetes mellitus (DM).Methods Adult male Wistar rats,weighing 160-180 g,were used in this study.Type 2 DM was induced by intraperitoneal streptozotocin (STZ) 30 mg/kg once a day for 2 consecutive days.Twenty-four animals with type 2 DM were randomly divided into 3 groups (n =8 each) using a random number table:sham operation group (group S),I/R group and propofol group (group P).Myocardial I/R was produced by occlusion of the anterior descending branch of left coronary artery for 30 min followed by 2 h reperfusion.Propofol was infused intravenously at 6 mg· kg-1 · h-1 starting from 10 min before ischemia until 2 h of reperfusion in group P.The animals were sacrificed after 2 h of reperfusion and myocardial specimens in the ischemic region were obtained for microscopic examination and for determination of cell apoptosis and expression of Bax,Bcl-2 and caspase-3.The apoptosis index (AI) was calculated.Results Compared with group S,the expression of Bcl-2,Bax and caspase-3 was significantly up-regulated,and AI was increased,and microscopic examination showed that pathological changes of myocardium were found in I/R and P groups.Compared with group I/R,the expression of Bax and caspase-3 was significantly down-regulated,Bcl-2 expression was up-regulated,AI was decreased,and the pathologic changes were attenuated in group P.Conclusion The mechanism by which propofol attenuates myocardial I/R injury is related to up-regulation of Bcl-2 expression,down-regulation of Bax and caspase-3 expression and inhibition of cell apoptosis in rats with type 2 DM. Key words: Propofol ;  Diabetes mellitus, type 2 ;  Myocardial reperfusion injury ;  Apoptosis