Mechanisms by which Angiotensin II Affects the Heart Rate of the Conscious Sheep
作者:
WARWICK LEE,
MANSEL ISMAY,
EUGENIE LUMBERS,
期刊:
Circulation Research
(OVID Available online 1980)
卷期:
Volume 47,
issue 2
页码: 286-292
ISSN:0009-7330
年代: 1980
出版商: OVID
数据来源: OVID
摘要:
Intravenous infusions of angiotensin II were given to conscious sheep. During these infusions, the pressor action of angiotensin was antagonized by concomitant infusion of sodium nitroprusside. Under these conditions, angiotensin produced a dose-dependent tachycardia. This dose-dependent tachycardia was not affected by propranolol and therefore it was not due to an action of angiotensin on sympathoadrenal mechanisms. The dose-dependent tachycardia was reduced by atro-pine, and abolished by increases in systolic pressure. We conclude that iv infusions of angiotensin cause a central, dose-dependent reduction in vagal tone. This action is normally antagonized by the barore-ceptor reflex response to the hypertensive action of angiotensin. Therefore, in those conditions in which endogenous angiotensin production is increased and blood pressure is not elevated (e.g., sodium deficiency and pregnancy), angiotensin may influence heart rate.Circ Res 47: 286-292, 1980
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