Direct myocardial effects of angiotensin II.
Direct myocardial effects of angiotensin II.
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血管紧张素 II 的直接心肌作用。
DOI：
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发表时间：
1971
影响因子：
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通讯作者：
T. Cooper
中科院分区：
文献类型：
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作者：
P. Dempsey;Z. T. McCallum;K. Kent;T. Cooper
彼得·登普西，泽娜·T肯尼思·麦卡勒姆肯特，和西奥多库珀。血管紧张素11的直接心肌效应。Am. J. Physiol.220（Z）：477-481。1971.-仍然存在关于血管紧张素II对心室肌的直接影响的推测。评价已复杂的外周循环在完整的制剂，反射机制的敏感性，以及关于神经节和内源性儿茶酚胺商店的作用的分歧。设计了两个系列的实验，使用来自正常猫和来自经历了外源性心脏去神经支配以消耗儿茶酚胺的猫的心脏。在第一个系列中，19个离体灌注心脏进行了研究，在Langendorff装置。在第二个系列中，记录了20个右心室乳头肌的张力和跨膜动作电位。在正常和失神经支配的心室肌中，血管紧张素（10 - 10 μ g/ml-10 - 10 μ g/ml）引起正性肌力作用，其特征在于增加最大张力上升速率和舒张速率，但不缩短达到峰值张力的时间。观察到动作电位2相形式的变化。这些数据表明，血管紧张素释放一个直接的正性肌力作用，这是独立于完整的肾上腺素能神经或内源性儿茶酚胺储存。
DEMPSEY, PETER J., ZENA T. MCCALLUM, KENNETH M. KENT, AND THEODORE COOPER. Direct myocardial efects of angiotensin 11. Am. J. Physiol. 220(Z) : 477-481. 1971.-There still remains speculation concerning the existence of a direct effect of angiotensin II on ventricular myocardium. Evaluation has been complicated by the sensitivity of the peripheral circulation in intact preparations, reflex mechanisms, and disagreement concerning the role of ganglia and endogenous catecholamine stores. TWO series of experiments were designed that used hearts from normal cats and from cats that had undergone extrinsic cardiac denervation to deplete catecholamines. In the first series, 19 isolated perfused hearts were studied in a Langendorff apparatus. In the second series, tension and transmembrane action potentials were recorded from 20 right ventricular papillary muscles. In normal and denervated ventricular myocardium angiotensin (lo--lo g/ml-lo-” g/ml) elicited a positive inotropic effect characterized by an increased maximum rate of tension rise and rate of relaxation, but not in a shortened time to peak tension. A change in the form of phase 2 of the action potential was noted. These data indicate that angiotensin elicits a direct positive inotropic effect which is independent of intact adrenergic nerves or endogenous catecholamine stores.