The Effects of Nifedipine on Acute Experimental Myocardial Ischemia and Infarction in Dogs
The Effects of Nifedipine on Acute Experimental Myocardial Ischemia and Infarction in Dogs
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硝苯地平对犬急性实验性心肌缺血和梗死的影响
DOI：
10.1161/01.res.44.1.16
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发表时间：
1979
影响因子：
20.1
通讯作者：
M. Klein
中科院分区：
文献类型：
--
作者：
A. Selwyn;E. Welman;K. Fox;P. Horlock;T. Pratt;M. Klein
我们研究了25只麻醉和胸部切开的狗，在急性局部心肌缺血前和5小时内。在主动脉窦内持续注入氪-81M(81mKr)。使用伽马相机和数字计算机，利用该示踪剂的心肌平衡来成像和评估局部心肌灌注的分布。在整个实验过程中记录心外膜心电图，测量S-T段抬高、R波丢失和Q波的出现，并测定主动脉和冠状动脉静脉血中肌酸激酶(CK)的活性。10只犬冠状动脉左前降支(LAD)狭窄5小时，不给药。5只犬在左前降支缩窄30分钟后静脉注射硝苯地平13μg/kg，另5只犬静脉注射1.0μg/kg。那些服用硝苯地平13μg/kg的狗显示，主动脉压下降了30%，心率上升了12%，局部缺血延长。心电图显示心肌梗死范围扩大，CK释放到冠状静脉的时间早于对照组。服用硝苯地平1μg/kg的狗显示，血压下降12%，心率没有增加，局部血流灌注改善，心电征象显示梗塞范围受到限制。冠状静脉肌酸激酶释放延迟。硝苯地平对局部心肌灌注、心电图和心脏酶释放的影响是剂量相关的，不能一概而论。这些观察结果值得进一步的临床研究，以改进该制剂在MAN中的使用。中国保监会第44：16-23号决议，1979
We studied 25 anesthetized and thoracotamized dogs before and during 5 hours of acute regional myocardial ischemia. Krypton-81m (81mKr) was infused constantly into the aortic sinuses. The myocardial equilibrium of this tracer was used to image and assess the distribution of regional myocardial perfusion using a gamma camera and digital computer. The epicardial ECG was recorded, S-T segment elevation and the loss of R and appearance of Q waves were measured, and the plasma activity of creatine kinase (CK) was determined in aortic and coronary venous blood throughout these experiments. Ten dogs underwent left anterior descending coronary artery (LAD) narrowing for 5 hours and received no drugs. Five dogs received nifedipine 13 μg/kg, and another five received 1.0 μg/kg intravenously 30 minutes after LAD narrowing. Those dogs receiving nifedipine, 13 μg/kg, showed a 30% fall in aortic pressure, a 12% rise in heart rate, and an extension of regional ischemia. The ECG showed an extension of infarct size, and CK release into the coronary vein appeared earlier than in the controls. Dogs receiving nifedipine, 1 μg/kg, showed a 12% fall in blood pressure, no rise in heart rate, an improvement in regional perfusion, and ECG signs that suggested limitation of infarct size. There also was delayed release of coronary venous CK. The effects of nifedipine on the natural history of regional myocardial perfusion, the electrocardiogram, and enzyme release from the heart were dose related and cannot be generalized. These observations warrant further clinical investigation to improve the use of this agent in man. Circ Res 44: 16-23, 1979