大鼠心肌缺氧缺血再灌注损伤及心肌重塑的相关研究

Correlation Study Between the Myocardial Anoxia Ischemia Reperfusion Injury and Myocardium Remodeling in Asphyxiated Newborn Rats.

目的观察窒息大鼠心肌缺氧缺血再灌注损伤后,心肌组织基质金属蛋白酶(matrix metal-loproteinases,MMPs)、转化生长因子-β1(transforming growth factor-β1,TGF-β1)的表达与损伤修复及窒息后心肌重塑的相关性。方法模拟大鼠常压窒息模型,制作缺氧缺血再灌注损伤大鼠动物模型。将60只7 d^10 d Wistar鼠,随机分成窒息组(n=45)和对照组(D组,n=15,不窒息处理)。窒息组根据窒息后复氧时间不同分为A,B,C组(分别为复氧后1 d,7 d,14 d),每组各15只。快速定量检测血清心肌肌钙蛋白Ⅰ(cardiac troponinⅠ,cTnⅠ),Masson染色测定胶原组织容积测算(collagen volume fraction,CVF),同时利用HE染色观察心肌组织病理学改变,免疫组化法测定心肌组织基质金属蛋白酶-3,-9的活性;免疫组化法进行定性及半定量分析心肌转化生长因子-β1的表达。结果血清心肌肌钙蛋白Ⅰ呈一过性增高,A组明显高于D组(P<0.01);B,C组下降,与D组比较,差异无显著意义(P>0.05)。心肌组织基质金属蛋白酶-3活性呈驼峰样增高,与D组比较,A,B,C组均升高,以B组升高最显著(P<0.05)。基质金属蛋白酶-9活性A,B,C组呈逐渐升高趋势,与D组比较,差异有显著意义(P<0.05)。窒息后,A,B,C组胶原组织容积测算值逐渐升高,A组与D组比较,差异无显著意义(P>0.05);B,C组与D组比较,差异有显著意义(P<0.01),且C组最高。A,B,C组转化生长因子-β1表达,随窒息时间延长而升高明显,A组与D组比较,差异无显著意义(P>0.05);B,C组与D组比较,差异有显著意义(P<0.01)。胶原组织容积与转化生长因子-β1表达呈正相关(r=0.574,P<0.01);基质金属蛋白酶-3,-9与胶原组织容积呈正相关(r=0.482,0.679;P<0.05)。结论新生鼠窒息后造成缺氧缺血再灌注损伤,心肌组织基质金属蛋白酶-3,-9激活,转化生长因子-β1表达增强,继发胶原组织容积增高。基质金属蛋白酶-3,-9与转化生长因子-β1,可能参与心肌与缺氧缺血再灌注损伤的自我修复损伤后心肌重塑。

Objective To observe the expression of matrix metalloproteinases （MMPs） and transforming growth factor-β1 （TGF-β1） and their effectiveness on myocardial repairing and remodeling after anoxia ischemia reperfusion injury in rats. Methods The anoxia ischemia reperfusion injury animal model was set up in this study. Sixty Wistar rats were randomly divided into 4 groups： the group A, B, C （at the first day, the seventh day and the fourteenth day after the myocardial anoxia ischemia reperfusion injury） and the control group（without any asphyxia treatment）（15 rats for each group）. The blood serum cardiac troponin Ⅰ （cTn Ⅰ ） was measured by the rapid quantifying. Masson staining was used to study the collagen volume fraction （CVF）, and myocardial histopathological integration was tested by the HE staining. The myocardial matrix metalloproteinase-3, 9 activities was measured by the immunohistochemical assay, and the transforming growth factor-β1 expression of myocardium were measured by the immunohistochemistry assay and semiquantitative analysis. Results Serum cardiac troponin Ⅰ provisionality raised, the level of the group A were obviously higher than those of the control group （P〈0.01）, but the level of the group B and C declined （P〉0.05）; matrix metalloproteinase-3 activity in the group A, B and C were significantly higher than those of the control group, reaching a peak on the group B （P〈0.05）. The metalloproteinase-9 activity in the group A, B and C were significantly higher than those of the control group （P〈0. 05）. Collegen volume fractions were gradually increased after asphyxia （P〉0.05, P〈0.05, P〈0.05, respectively） and the group C reached the highest level. The expression of transforming growth factor-β1 enhanced by the change of the time（P〉0. 05, P〈0. 01, P〈0. 01, respectively）. Collegen volunm fractions were positively correlated with transforming growth factor-β1 （r = 0. 574, P〈0. 01 ）. Matrix metalloproteinase-3, -9 activities positively correlated with collegen volume fractions （r= 0. 482, 0. 679; P〈0.05）. Conclusion There has anoxia ischemia reperfusion injury in rats myocardium. After the asphyxia, the matrix metalloproteinase 3, -9 activities are activited and the expression of transforming growth factor-β1 are enhanced, myocardial collagens increase. Matrix metalloproteinase-3, 9, transforming growth factor-β1 may relate with the myocardial remodeling after the anoxia ischemia reperfusion injury.