Danielsen C C, Wiggers H, Andersen H R
Department of Connective Tissue Biology, Skejby University Hospital, University of Aarhus, Denmark.
J Mol Cell Cardiol. 1998 Jul;30(7):1431-42. doi: 10.1006/jmcc.1998.0711.
We studied the presence of collagen degrading enzymes (matrix metalloproteinases, MMPs) in porcine myocardium following ischemia and late reperfusion. In nine pigs, left anterior descending coronary artery was occluded for 6 h followed by reperfusion for 3 h. Six pigs without coronary occlusion served as controls. After the reperfusion period, transmural biopsies from the anterior (ischemic zone) and posterior wall (non-ischemic myocardium) in the left ventricle were obtained and extracted. Heparin-Sepharose isolated components in extracts were analysed for collagenase (triple-helical collagen degradation) and gelatinase activity (zymography). Immunohistochemistry using anti-human (MMP-1, MMP-2, MMP-9, and fibronectin) antibodies was performed on additional biopsies. Collagenase (MMP-1) and gelatinases (MMP-2, MMP-9) could be demonstrated in the extracts of non-ischemic myocardium from ischemic/reperfused as well as control pigs and MMP-1 and MMP-9 activity was found to be increased in ischemic/reperfused myocardium compared with non-ischemic myocardium. In ischemic/reperfused myocardium from live pigs investigated, myocyte necrosis could be confirmed by fibronectin immunoreaction in myocytes and MMP-1 and MMP-9 immunoreactions were increased. MMP-9 was present in cells likely to be infiltrating leukocytes in a patchy distribution throughout the ischemic myocardium. Quite coincident with MMP-9 positive cells, MMP-1 immunoreaction appeared in necrotic myocytes, in addition to reactions observed in vessel walls, endo- and epicardium, and extracellular matrix in non-ischemic myocardium. Thus, the results showed increased amounts of collagenase (MMP-1) and gelatinase (MMP-9) in ischemic/ reperfused myocardium, indicating the appearance of increased amounts of collagen degrading enzymes very early following ischemia and late reperfusion.
我们研究了猪心肌在缺血和晚期再灌注后胶原降解酶（基质金属蛋白酶，MMPs）的存在情况。在9只猪中，左前降支冠状动脉闭塞6小时，随后再灌注3小时。6只未进行冠状动脉闭塞的猪作为对照。再灌注期结束后，获取并提取左心室前壁（缺血区）和后壁（非缺血心肌）的透壁活检组织。对提取物中肝素-琼脂糖分离的成分进行胶原酶（三螺旋胶原降解）和明胶酶活性（酶谱分析）分析。对额外的活检组织进行使用抗人（MMP-1、MMP-2、MMP-9和纤连蛋白）抗体的免疫组织化学分析。在缺血/再灌注猪以及对照猪的非缺血心肌提取物中可检测到胶原酶（MMP-1）和明胶酶（MMP-2、MMP-9），并且发现缺血/再灌注心肌中的MMP-1和MMP-9活性相较于非缺血心肌有所增加。在所研究的存活猪的缺血/再灌注心肌中，通过肌细胞中的纤连蛋白免疫反应可证实肌细胞坏死，且MMP-1和MMP-9免疫反应增强。MMP-9存在于整个缺血心肌中呈斑片状分布的可能为浸润白细胞的细胞中。与MMP-9阳性细胞相当一致的是，除了在非缺血心肌的血管壁、心内膜和心外膜以及细胞外基质中观察到的反应外，MMP-1免疫反应还出现在坏死的肌细胞中。因此，结果显示缺血/再灌注心肌中胶原酶（MMP-1）和明胶酶（MMP-9）的量增加，表明在缺血和晚期再灌注后很早就出现了胶原降解酶量的增加。
