Abstract: Abstract: Objective To analyze the effect of co-stress of myocardial ischemia(MI) and cold on myocardium in rats,and investigate the role and relative mechanism of atorvastatin intervention in such co-stress.Methods Co-stress model was induced by ligation of left coronary artery combined with cold stress of 4℃,8h/d for 4 consecutive days.Rats were gavaged with atorvastatin 20mg.kg-1.d-1 for 3 days before MI was induced and thereafter for 4 days.Cardiac function was assessed by echocardiography;myocardial infarct size was determined by TTC staining;p- PI3K,p-GSK3β,Bim and Caspase-3 expression in myocardium was determined by western blotting.Results It was demonstrated that co-exposure of myocardial ischemia and cold stress could significantly deteriorate the cardiac function and increase the infarct size (P<0.01),and this was attenuated by atorvastatin use with increased expression of p-PI3K,p-GSK3β and Bim, Caspase3 downregulating(P<0.01).Conclusion Co-exposure to myocardial ischemia and cold stress aggravate the cardiac injury, this influence can partially attenuated by atrovastatin use and the mechanism may be attributed to activation of PI3K/Akt/GSK3β and decreasing expression of Bim.

Key words: myocardial infarction, cold stress, atorvastatin, Bim