Release of Adrenal Catecholamines by Angiotensin II
Release of Adrenal Catecholamines by Angiotensin II
复制标题
血管紧张素 II 释放肾上腺儿茶酚胺
作者：
M. Peach;W. Cline;D. T. Watts
最近的几项研究已经提出了血管紧张素刺激肾上腺髓质儿茶酚胺释放的间接证据。进行了以下工作，试图通过分析血浆儿茶酚胺来显示肾上腺髓质的体内血管紧张素刺激。用戊巴比妥麻醉的杂种犬，以0.025、0.05和0.1 μg/kg/min的剂量输注血管紧张素10 min或以0.5、1.0和2.0 μg/kg的单次剂量注射。在单次给药的升压反应峰值或输注期间和输注后，从下腔静脉（肾上腺静脉流出液上方）采集血样。对样本进行肾上腺素和去甲肾上腺素荧光分析。结果发现，血管紧张素增加循环中的儿茶酚胺。每分钟输注0.05和0.1 μg/kg和所有三种注射剂量的肾上腺素显著增加。除注射0.5 μg/kg剂量的血管紧张素外，血浆去甲肾上腺素也显著增加。血管紧张素输注0.025 μg/kg/min未引起循环儿茶酚胺水平的可检测变化。在输注实验中，去甲肾上腺素的增加比肾上腺素更短暂。这些结果表明，不同升压剂量的血管紧张素刺激肾上腺儿茶酚胺的释放。
Several recent investigations have presented indirect evidence that angiotensin stimulates the release of adrenal medullary catecholamines. The following work was undertaken in an attempt to show in vivo angiotensin stimulation of the adrenal medulla by analysis of plasma catecholamines. Mongrel dogs, anesthetized with pentobarbital, were infused for 10 min with doses of 0.025, 0.05, and 0.1 μg per kg per min of angiotensin or injected with single doses of 0.5, 1.0 and 2.0 μg per kg. Blood samples were taken from the inferior vena cava (above the outflow from the adrenal veins) at the peak of the pressor responses to single doses or during and after the infusions. The samples were fluorometrically analyzed for epinephrine and norepinephrine. It was found that angiotensin produced an increase in circulating catecholamines. Epinephrine was significantly increased by infusions of 0.05 and 0.1 μg per kg per min and all three injected doses. Plasma norepinephrine was significantly increased also except with the 0.5 μg per kg injected dose of angiotensin. Angiotensin infusion of 0.025 μg per kg per min did not cause a detectable change in circulating catecholamine levels. In the infusion experiments, norepinephrine was more transiently increased than epinephrine. These results show that various pressor doses of angiotensin stimulate release of adrenal catecholamines.