大鼠心脏缺血再灌注对心肌基质金属蛋白酶-1的影响(英文)

THE EFFECT OF ISCHEMIA-REPERFUSION ON MATRIX METALLOPROTEINASE-1 IN RAT HEART

目的探讨缺血和缺血-再灌注状态下对大鼠心肌基质金属蛋白酶-1(MMP-1)的影响。方法取正常大鼠心脏和通过钳夹大鼠心脏冠状动脉旋支制造缺血-再灌注模型的心肌组织,利用免疫组织化学、Westernblotting技术和计算机图像处理系统,对正常和缺血-再灌注大鼠心脏MMP-1的表达进行形态学观察,并对其含量进行定量分析。结果1.免疫组织化学反应显示正常心脏的MMP-1主要分布于心肌的细胞间质。纤维细胞、血管平滑肌细胞、毛细血管内皮细胞均呈强阳性反应。缺血30min心肌MMP-1反应无明显变化,缺血60min,酶反应浓度明显增加,缺血-再灌注30min,MMP-1的阳性反应增强,缺血-再灌注60min后,MMP-1反应区出现大面积融合。2.定量分析显示,缺血30min,MMP-1无显著性改变(P>0.05);缺血60min,出现显著性改变(P<0.05);缺血-再灌注30min,有显著性改变(P<0.01);缺血-再灌注60min,出现高度显著性改变(P<0.001)。3.Western blotting显示,缺血30min、60min肉眼观察无明显变化。缺血-再灌注30min,MMP-1条带开始增宽,缺血-再灌注60min,MMP-1条带显著增宽。结论1.正常情况下MMP-1由毛细血管内皮、心内膜的内皮、小动脉平滑肌细胞分泌;在缺血、再灌注情况下心肌细胞具有分泌MMP-1的潜能。2.随心肌缺血时间的延长,MMP-1的含量逐渐增多,再灌注可进一步增加MMP-1的含量,这可能是心肌缺血-再灌注后胶原迅速破坏的主要原因之一。

Objective To investigate the effect of ischemia and isehemia/repeffusion（I/R） in rat heart on matrix metalloproteinase-1（MMP-1）. Methods The I/R animal models were established by shutting down and reopening the anterior interventricnlar branch with a silver clamp, then the distribution and amount of MMP-1 of the normal and I/R rat hearts were observed by immunohistochemical staining and Western blotting and analyzed by computer image analysis. Results 1. Immunohistochemical staining showed MMP-1 existed mainly in the cardiac matrix. There were strong positive reactions in fibrocytes, smooth muscle cells of the blood vessel and endothelial cells of capillaries. MMP-1 didn＇t show distinct changes 30 minutes after ischemia, while its concentration increased dramatically 60 minutes after ischemia. The positive reaction of MMP-1 increased 30 minutes after I/R, and 60 minutes after I/R there was large fusion areas in MMP-1 existing regions. 2. Quantitative analysis showed no dramatic changes of MMP-1 after ischemia for 30 minutes（ P 〉 0.05）, while dramatic changes were seen 60 minutes after ischemia（ P 〈 0.05）. MMP-1 changed dramatically 30 minutes and 60 minutes after I/R. 3. Western blotting showed that there were no distinct naked-eye-observable changes.The bands of MMP-1 became widened 30 minutes after I/R, and became obviously widened 60 minutes after I/R. Conclusion 1. MMP-1 is secreted by fib rocytes, smooth muscle cells and endothelial cells of cardiac tissue under physiological conditions,and cardiomyocytes has the potential to secrete MMP-1 under isehemia or I/ R. 2. The longer time the heart ischemia lasts, the greater MMP-1 concentration will increase. Reperfusion can increase MMP-1 concentration to an even higher level,which may be the main cause of the collagen destruction after heart I/R.