Metoprolol attenuates postischemic depressed myocardial function in papillary muscles isolated from normal and postinfarction rat hearts.
Metoprolol attenuates postischemic depressed myocardial function in papillary muscles isolated from normal and postinfarction rat hearts.
复制标题
美托洛尔可减弱从正常和梗塞后大鼠心脏分离的乳头肌中缺血后抑制的心肌功能。
DOI：
10.1016/s0014-2999(01)01050-0
复制
发表时间：
2001
影响因子：
5
通讯作者：
Morgan,JP
中科院分区：
文献类型：
--
作者：
Min,JY;Ding,B;Wang,JF;Sullivan,MF;Morgan,JP
The present study was designed to test the hypothesis that metoprolol treatment may enhance tolerance to ischemia in normal and postinfarction rat myocardium. Myocardial infarction was induced by permanent ligation of the left coronary artery in adult rats. Animals were divided into sham-operated and infarction groups with or without metoprolol treatment. Metoprolol treatment (60 mg/kg/day via gastric gavage) was started on the second day after surgery and continued until sacrifice at 6 weeks after myocardial infarction. Isometric force and intracellular Ca2+([Ca2+]i) transients were simultaneously recorded in isolated left ventricular papillary muscles. Ischemia was simulated by immersing the muscles into fluorocarbon with hypoxia. Metoprolol treatment induced a significant improvement of isometric force and ameliorated diastolic [Ca2+]ioverload in postinfarction rat myocardium at baseline. Metoprolol treatment also reduced diastolic [Ca2+]i, ameliorated the depression of developed tension during ischemia, and enhanced recovery of postischemic depressed myocardial function in sham-operated and postinfarction rat papillary muscles. Protein levels of the sarcoplasmic reticulum Ca2+ATPase of left ventricles and postischemic papillary muscles from metoprolol-treated rats were higher than those in placebo-treated animals. We concluded, therefore, that metoprolol treatment produced appreciable improvement of intracellular Ca2+handling during ischemia–reoxygenation cycles, and enhanced recovery of postischemic depressed myocardial function in both normal and postinfarction rat myocardium.
