1,6-二磷酸果糖预先给药对大鼠急性心肌缺血时缝隙连接蛋白43的影响

摘要：Objective To investigate the effect of fructose-1,6-diphosphate (FDP) pretreatment on myocardial connexin 43 (Cx43) in a rat model of acute myocardial ischemia.Methods Thirty-six male Sprague Dawley rats (aged 8-12 weeks and weighing 220-280 g) were randomly divided into three groups (n =12 each):sham operation group (group S),ischemia group (group Ⅰ) and FDP + ischemia group (group F).The animals were anesthetized with intraperitoneal injection of 10％ chloral hydrate 40 mg/100 g,then tracheostomized and mechanically ventilated.Acute myocardial ischemia was induced by occlusion of the left anterior descending coronary artery for 30 minutes.Myocardial ischemia was verified by elevation of the S-T segment on echocardiogram (EGG).In group F,FDP 100 mg/kg was injected intravenously 10 minutes before ischemia.The hearts were removed after 30 minutes of myocardial ischemia.The myocardial infarct size (IS) and area at risk (AAR) were measured and the IS/AAR ratio was calculated.The expression of myocardial Cx43 protein was determined by immunohistochemestry and analysis of mean optical density.Results The severities of arrhythmia were significantly higher in groups F and I than in group S,while lower in group F than in group Ⅰ (P＜ 0.05).The IS/AAR ratio was significantly lower in group F than in group Ⅰ.The myocardial Cx43 protein expression was down-regulated in group Ⅰ and group F as compared with group S,and was significantly lower in group Ⅰ than in group F.Conclusion FDP pretreatment can protect myocardium against acute ischemia by up-regulation of myocardial Cx43 expression.