大鼠急性心肌梗死后心肌组织整合素连接激酶表达的变化

目的观察实验性大鼠急性心肌梗死后不同时间点心肌整合素连接激酶表达水平和心功能的动态变化,探讨心肌梗死后心功能不全和整合素连接激酶表达变化的关系。方法成年雄性SD大鼠,开胸结扎左冠状动脉前降支建立心肌梗死模型,在心肌梗死后不同时间点分别用超声心动图和左心室导管评估心功能,实时定量PCR和Western blotting检测非梗死区心肌组织内整合素连接激酶表达。结果与假手术组相比,心肌梗死组心功能明显下降。在心肌梗死后第1、4和8周三个时间点中,第8周组±dp/dtmax明显低于第1周组和第4周组,左心室舒张末压明显高于第1周组和第4周组。实时定量PCR和Western blotting检测发现,非梗死区心肌整合素连接激酶表达水平在心肌梗死后第1、4周显著升高,第8周表达降低,回落到假手术组水平,且明显低于心肌梗死后第1、4周。结论心肌梗死后非梗死区心肌组织内整合素连接激酶由短期内的表达增加到长期的表达减少,可能参与心肌梗死后心功能由代偿到失代偿的发展过程。

Integrin-Linked Kinase Expression in Myocardium After Acute Myocardial Infarction in Rats

Aim To investigate the role of integrin-linked kinase(ILK) during progressive heart dysfunction after acute myocardial infarction(AMI),and observe the changes of heart function as well as ILK expression at different time points after AMI. Methods Left anterior descending arteries of adult male SD rats were ligated to form AMI models.Cardiac function was evaluated by echocardiography and left ventricular catheter.Real time PCR and Western blotting were used to assess ILK expression in non-infarct area.The above parameters were examined in different time points after post AMI. Results After AMI,heart function was significantly decreased.Lower of ±dp/dtmax and higher left ventricular end diastolic pressure(LVEDP) of 8 weeks group was observed,compared with 1 and 4 weeks groups post AMI.On the other hand,ILK expression of non-infarct area was increased in 1 and 4 weeks groups and decreased significantly in 8 weeks group post AMI. Conclusion Although temporary ILK up-expression in non-infarct area post acute myocardial infarction maintains compensatory cardiac function,long-term down-regulation of ILK pathway finally lead to cardiac decompensation.