Widman S C, Liang C S, Schenk E A, Hood W B
Department of Medicine, University of Rochester Medical Center, New York 14642.
J Cardiovasc Pharmacol. 1994 Nov;24(5):694-701.
Contraction band necrosis (CBN) may represent infarct extension from free radical generation during reperfusion. We sought to limit CBN with the free radical scavenger N-2-mercaptopropionyl glycine (MPG, 20 mg/kg). Sixteen chronically instrumented Beagles (8 control, and 8 MPG treated) underwent 90-min left anterior descending coronary artery (LAD) occlusion followed by 6-h reperfusion. Coronary blood flow (CBF) was measured by the radioactive microsphere technique. The dogs were killed, and the hearts were perfused with red and blue dyes to determine area at risk (AAR), stained with nitroblue tetrazolium for infarct localization, and sectioned for histologic analysis and BF measurements. In controls and MPG-treated animals, infarct/risk ratios were 40 +/- 5 and 38 +/- 6%, and epicardial collateral BFs were 0.21 +/- 0.037 and 0.15 +/- 0.034 ml/g/min, respectively (p = NS). Hemodynamic measurements did not differ between the two groups. However, CBN as a percentage of total infarct was reduced in controls (22 +/- 3%) as compared with MPG-treated animals (35 +/- 2%, p = 0.002). Thus, MPG altered the histologic composition of infarcts in this model, surprisingly increasing the amount of CBN without altering overall infarct size (IS). These results raise questions about the role of free radical scavengers in generation of CBN and suggest that a population of cells exists in which treatment with MPG may alter the mechanism of cell death.
收缩带坏死（CBN）可能代表再灌注期间自由基生成导致的梗死扩展。我们试图用自由基清除剂N-2-巯基丙酰甘氨酸（MPG，20mg/kg）来限制CBN。16只长期植入仪器的比格犬（8只对照，8只接受MPG治疗）经历了90分钟的左冠状动脉前降支（LAD）闭塞，随后再灌注6小时。通过放射性微球技术测量冠状动脉血流量（CBF）。处死犬只，用红色和蓝色染料灌注心脏以确定危险区域（AAR），用硝基蓝四氮唑染色以定位梗死灶，并切片进行组织学分析和BF测量。在对照动物和接受MPG治疗的动物中，梗死/危险比值分别为40±5%和38±6%，心外膜侧支BF分别为0.21±0.037和0.15±0.034ml/g/min（p=无显著性差异）。两组之间的血流动力学测量结果无差异。然而，与接受MPG治疗的动物（35±2%，p=0.002）相比，对照组中CBN占总梗死灶的百分比降低。因此，在该模型中，MPG改变了梗死灶的组织学组成，令人惊讶的是，它增加了CBN的量，而没有改变总体梗死面积（IS）。这些结果对自由基清除剂在CBN生成中的作用提出了疑问，并表明存在一群细胞，用MPG治疗可能会改变细胞死亡的机制。
