Cardiovascular and hormonal response to hemorrhage in conscious rats.
Cardiovascular and hormonal response to hemorrhage in conscious rats.
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清醒大鼠对出血的心血管和激素反应。
DOI：
10.1152/ajpheart.1988.254.5.h947
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发表时间：
1988
期刊：
影响因子：
--
通讯作者：
Naray-Fejes-Toth,A
中科院分区：
文献类型：
--
作者：
Fejes-Toth,G;Brinck-Johnsen,T;Naray-Fejes-Toth,A
The effect of arginine vasopressin (AVP) pressor blockade on the response to graded hemorrhage was investigated on conscious, unstressed, freely moving rats. The parameters studied were mean arterial pressure (MAP), heart rate (HR), blood velocity in the ascending aorta (ABV), and plasma concentrations of AVP (pAVP), renin (PRC), corticosterone (pCS), and catecholamines. After the first hemorrhage (0.75% of body wt over 5 min), MAP remained unchanged while ABV declined and HR increased. The two subsequent hemorrhages brought about significant reduction in MAP, HR, and ABV. pAVP, pCS, and PRC increased gradually during the experiment, while plasma catecholamine levels remained unchanged except for epinephrine, which increased after the third hemorrhage. After pretreatment with the AVP-pressor antagonist, [d(CH2)5Tyr(Me)]AVP, the hemorrhage-induced cardiovascular changes were practically identical to those seen in control animals. Results with AVP blockade performed after the third hemorrhage were also negative. A pressor role of AVP after hypotensive hemorrhage could only be revealed in the presence of converting-enzyme inhibition and alpha-adrenergic blockade. In addition, [d(CH2)5Tyr(Me)]AVP did not modify the effect of hemorrhage on pCS and catecholamines and caused only a slight enhancement of the increase in PRC. It is concluded that conscious, nonstressed rats, if all compensatory mechanisms are allowed full expression, exhibit a normal cardiovascular compensatory response to hemorrhage in the absence of functional AVP pressor receptors.
