大鼠心肌缺血/再灌注损伤及预处理apelin的表达

目的观察大鼠心肌缺血/再灌注损伤及预处理中apelin表达变化,探讨其可能的作用。方法SD大鼠60只随机分成4组:缺血/再灌注组(IR),预处理组(IP),假手术组(SH)和正常对照组(NC)。放免法测定血浆及心肌apelin-36蛋白含量,免疫组化法观察心肌apelin的表达,RT-PCR方法探讨大鼠心肌apelin mRNA表达。结果(1)血浆、心肌组织apelin-36浓度:IR的含量分别比NC低36.1%、45.6%(P<0.01),IP分别比NC低23.8%、24.7%(P<0.01)。SH与NC、IR与IP比无差异(P>0.05)。(2)apelin免疫组化染色吸光度值:IR与IP比NC分别低65.3%和36.8%(P<0.01,P<0.05),IR比IP低45.1%(P<0.05)。SH与NC无差别(P>0.05)。(3)心肌apelin mRNA的水平:IR是NC的40.2%(P<0.01),IP为NC的65.2%(P<0.05),IR是IP组的38.3%(P<0.05),SH与NC无差别(P>0.05)。结论在心肌缺血/再灌注损伤及预处理过程中,大鼠血浆及心肌组织apelin-36蛋白及基因表达下调,提示apelin在该病理生理过程中可能有重要作用。

The Expression of Apelin in Rat Myocardial Ischemic Preconditioning and Ischemia/Reperfusion Injury

Objective To observe the change of apelin in myocardial ischemic preconditioning and ischemia/reperfusion injury of rats and study the role of apelin.Methods Sixty SD rats were randomly divided into four groups: ischemia/reperfusion group(IR);ischemia pre-conditioning group(IP);sham operation group(SH) and the normal control group(NC).The protein level of apelin-36 in myocardium and plasma were detected by radiommunoassay.The expression of Apelin was observed in left ventricle myocytes by immunohistochemistry.The expression of apelin mRNA was investigated in left ventricle myocardium by RT-PCR.Results(1) The apelin-36 protein level of plasma and myocardium in IR were lower by 36.1% and 45.6% respectively than NC(P<0.01),and in IP were 23.8% and 24.7% respectively(P<0.01).There was no significant difference between SH with NC,IR with IP(P>0.05).(2)The staining absorbance of apelin in IR and IP were lower by 65.3% and 36.8% respectively than NC(P<0.01,P<0.05).IR was lower by 45.1% than IP(P<0.01).There was no differences between SH and NC(P>0.05).(3) The expression of Apelin mRNA in left ventricle myocardium in IR and IP were 40.2% and 65.2% of NC respectively(P<0.01,P<0.05),and IR was 38.3% of IP(P<0.05).There was no difference between SH and NC(P>0.05).Conclusion The decreased expression of apelin-36 gene and protein in the plasma and myocardium of rats indicated that apelin might be involved in the pathogenesis and it has an important role in myocardial ischemic pre-conditioning and ischemia/reperfusion injury.