Central effect of angiotensin II on baroreflex regulation in conscious rabbits.
Central effect of angiotensin II on baroreflex regulation in conscious rabbits.
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DOI：
10.1152/ajpregu.1989.256.3.r694
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发表时间：
1989-03
期刊：
影响因子：
--
通讯作者：
Y. Matsumura;E. Hasser;V. S. Bishop
中科院分区：
文献类型：
--
作者：
Y. Matsumura;E. Hasser;V. S. Bishop
在清醒的兔子中检查了血管紧张素 II (ANG II) 对肾交感神经活动 (RSNA) 和心率 (HR) 的动脉压力反射控制的中枢作用。与去氧肾上腺素（PE）（0.5-16微克.kg-1.min-1）相比，静脉输注ANG II（5-320 ng.kg-1.min-1）显着降低HR的压力反射抑制，而RSNA的反射抑制未改变。背景静脉输注 ANG II 不会改变 RSNA 或 HR 的压力反射反应，以增加（使用 PE）或降低平均动脉压（使用硝酸甘油或下腔静脉封堵器）。当 ANG II 输注至椎动脉 (VA) 时，综合升压反应大于静脉输注。与静脉输注相比，ANG II 的渐进 VA 输注导致 HR 的压力反射抑制显着减弱，而 VA 和静脉输注之间的 RSNA 反射抑制是相同的。这些结果表明，ANG II 通过后脑位点产生中枢升压作用，并减少 HR 的压力反射抑制，而不改变 RSNA 的压力反射抑制。
Central effects of angiotensin II (ANG II) on arterial baroreflex control of renal sympathetic nerve activity (RSNA) and heart rate (HR) were examined in conscious rabbits. Intravenous infusions of ANG II (5-320 ng.kg-1.min-1) significantly reduced the baroreflex inhibition of HR compared with phenylephrine (PE) (0.5-16 micrograms.kg-1.min-1), whereas reflex inhibition of RSNA was unaltered. Background intravenous infusions of ANG II did not alter the baroreflex responses of RSNA nor HR to increases (with PE) or decreases in mean arterial pressure (with nitroglycerin or inferior vena cava occluder). When ANG II was infused into the vertebral artery (VA) the integrated pressor response was greater than intravenous infusions. Progressive VA infusions of ANG II resulted in a significantly blunted baroreflex inhibition of HR compared with intravenous infusions, whereas the reflex inhibition of RSNA was identical between VA and intravenous infusions. These results suggest that ANG II produces central pressor effects via a hindbrain site and reduces baroreflex inhibition of HR without altering baroreflex inhibition of RSNA.