Pressure dependence of the canine aortic characteristic impedance and the effects of alterations in smooth muscle activity

被引：14

作者：

Stone, D.N. ^{[1
]}

Dujardin, J.-P.L. ^{[1
]}

机构：

[1] Department of Physiology, The Ohio State University, Columbus, OH 43210, United States

来源：

Medical and Biological Engineering and Computing | 1985年 / 23卷 / 04期

关键词：

BIOLOGICAL MATERIALS - Muscle - PRESSURE EFFECTS - Measurements;

D O I：

10.1007/BF02441585

中图分类号：

学科分类号：

摘要：

Experiments were performed on anesthetized dogs to separate the effects of changes in aortic smooth muscle activity on the characteristic impedance Z//c from its passive pressure dependence. Z//c was measured from the ascending aortic pressure/flow relationship in a wide pressure range caused by forced slow oscillations in pressure induced with an external pump. Changes in smooth muscle tone were elicited by hemorrhage, two levels of volume expansion and alpha-adrenergic blockade with phenoxybenzamine. Curves relating Z//c to pressure usually showed a minimum. When analyzed at a given pressure hemorrhage increased Z//c whereas both volume expansions and alpha blockade reduced Z//c over a wide pressure range. In the case of hemorrhage, the total increase in Z//c was shown to be the sum of a passive pressure-dependent component and an active (pressure-independent) component.

引用

页码：324 / 328