Effect of Stimulation of Carotid Chemoreceptors on Total and Regional Cerebral Blood Flow
作者:
DONALD HEISTAD,
MELVIN MARCUS,
JAMES EHRHARDT,
FRANCOIS ABBOUD,
期刊:
Circulation Research
(OVID Available online 1976)
卷期:
Volume 38,
issue 1
页码: 20-25
ISSN:0009-7330
年代: 1976
出版商: OVID
数据来源: OVID
摘要:
This study was performed to determine whether stimulation of the carotid chemoreceptors increases total or regional cerebral blood flow and whether activation of arterial chemoreceptors contributes to cerebral vasodilation during systemic hypoxemia. In anesthetized and ventilated dogs, carotid chemoreceptors were stimulated with nicotine or hypoxic and hypercapnic blood. To measure total and regional cerebral blood flow, we used labeled 15-μ microspheres. Stimulation of chemoreceptors did not increase cerebral blood flow or produce significant redistribution of cerebral blood flow, even though the chemoreflex was intact in these animals (as manifested by vasoconstriction in muscle, kidney, and small bowel) and the cerebral vessels dilated in response to systemic hypercapnia. In other studies in anesthetized, ventilated dogs and rhesus monkeys, cerebral vasodilator responses to systemic hypoxemia were observed before and after denervation of carotid and aortic chemoreceptors. Systemic hypoxemia produced large and equivalent increases in cerebral blood flow before and after chemodenervation. We conclude that stimulation of carotid chemoreceptors does not produce cerebral vasodilation and that chemoreceptors do not contribute significantly to cerebral vasodilation during systemic hypoxemia.
点击下载:
PDF
(1391KB)
返 回