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目的 探讨老年大鼠心肌缺血再灌注损伤 (IRI)时氧自由基 (OFR)与细胞间粘附分子 - 1 (ICAM -1 )的变化及其相互关系。方法 Wistar大鼠 1 1 2只 ,制作心肌IRI模型 ,设青、老年组 ;各组分设缺血 1小时 ,再灌注 3、 6、 1 2和 2 4小时时相点 ,用免疫组化法测ICAM - 1蛋白表达水平 ,用酶法测定中性粒细胞 (PMNs)浸润数 ,用硫代巴比妥酸比色法测定心肌组织丙二醛 (MDA) ,用黄嘌呤过氧化物酶法测定超氧化物歧化酶 (SOD)活性 ,TTC染色法测定梗死范围。结果 心肌IR时 ,青、老年组ICAM - 1蛋白质表达、PMNs浸润、心肌梗死范围、MDA含量均明显增高 ,SOD活性显著降低。但MDA、SOD达峰、谷值的时间早于ICAM - 1表达及PMNs浸润的峰值。这些指标老年组变化更明显。结论 心肌缺血再灌注时 ,OFR的增加促进了ICAM - 1表达的上调 ,继之激活PMN ,产生大量的OFR使心肌损伤加重。这种变化在老年大鼠中表现尤为显著 ,可能是导致其损伤较青年组严重的重要因素之一
Objective To investigate the changes of oxygen free radical (OFR) and intercellular adhesion molecule - 1 (ICAM - 1) in the aged rats with myocardial ischemia - reperfusion injury (IRI) and their correlation. Methods One hundred and twenty-two Wistar rats were used to make the model of myocardial IRI. The rats were divided into the young and old groups. The ischemia and ischemia groups were divided into 1 hour, 3, 6, 12 and 24 hours after reperfusion. Immunohistochemistry The expression of ICAM - 1 was detected by enzyme - spectrophotometry. The infiltration of neutrophils (PMNs) was measured by enzymatic method. The myocardial malondialdehyde (MDA) was measured by thiobarbituric acid colorimetric method. The level of ICAM - 1 was measured by xanthine peroxidase Superoxide dismutase (SOD) activity, TTC staining method to determine infarct size. Results In IR group, ICAM - 1 protein expression, PMNs infiltration, infarct size and MDA content were significantly increased and SOD activity was significantly decreased in the aged and elderly patients. However, the peak time and peak value of MDA and SOD were earlier than the peak of ICAM - 1 expression and PMNs infiltration. The indicators of elderly changes more significantly. Conclusion The increase of OFR promotes the up - regulation of ICAM - 1 expression during myocardial ischemia and reperfusion, followed by the activation of PMN and the generation of large amounts of OFR, which leads to the increase of myocardial injury. This change is particularly pronounced in aged rats, which may be one of the most important causes of injury in this group