Biblioteca Virtual en Salud

Objective To evaluate the effects of N-acetycysteine on the expression of caveolin-3 (Cav-3) during myocardial ischemia-reperfusion (I/R) in diabetic rats.Methods Twenty-four pathogenfree healthy adult male Sprague-Dawley rats,weighing 230-270 g,were divided into 3 groups (n =8 each) using a random number tablemyocardial I/R group (group I/R),diabetes mellitus plus myocardial I/R group (group D) and N-acetycysteine group (group NAC).Diabetes mellitus was induced by injection of streptozotocin 60 mg/kg via the tail vein and confirmed by blood glucose ≥ 16.7 mmol/L 3 days later.At 1 week after successful establishment of the model,N-acetycysteine 1.5 g · kg-1 · d-1 was injected through a gastric tube into stomach for 4 consecutive weeks in group NAC,and the equal volume of normal saline was given for 4 consecutive weeks in I/R and D groups.Myocardial I/R was then induced by 30 min ligation of the left anterior descending branch of the coronary artery followed by 2 h of reperfusion.At the end of reperfusion,the myocardial infarct size was determined by triphenyl tetrazolium chloride staining,the levels of serum creatine kinase-MB (CK-MB) and 15-F2t-Isoprostane were measured by enzyme-linked immunosorbent assay,and the expression of myocardial Cav-3,Akt,phosphor-Akt (p-Akt),endothelial nitric oxide synthase (eNOS) and phosphor-eNOS (p-eNOS) was detected by Western blot.Results Compared with group I/R,the myocardial infarct size and levels of serum CK-MB and 15-F2t-Isoprostane were significantly increased,and the myocardial Cav-3,p-Akt and p-eNOS expression and NO level were decreased in group D (P＜0.05).Compared with group D,the myocardial infarct size and levels of serum CK-MB and 15-F2t-Isoprostane were significantly decreased,and the myocardial Car-3,p-Akt and p-eNOS expression and NO level were increased in group NAC (P＜0.05).Conclusion N-acetycystein can activate Akt/eNOS/NO signaling pathway through up-regulating myocardial Cav-3 expression,thus reducing myocardial I/R injury in diabetic rats.