Vagal cardiopulmonary baroreflex activation during phenylephrine infusion.
Vagal cardiopulmonary baroreflex activation during phenylephrine infusion.
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去氧肾上腺素输注期间迷走神经心肺压力反射激活。
DOI：
10.1152/ajpregu.1989.257.5.r1147
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发表时间：
1989
期刊：
影响因子：
--
通讯作者：
Thames,MD
中科院分区：
文献类型：
--
作者：
Minisi,AJ;Dibner-Dunlap,M;Thames,MD
为研究窦-主动脉压力感受器反射(SAB)所介导的反射反应，应用去甲肾上腺素(PE)升高动脉压(BP)。据报道，在PE期间心脏充盈压升高。我们的实验确定了PE是否选择性地激活SAB而不激活迷走心肺压力反射(CPR)。在去窦弓神经(SAD；n=10)、选择性迷走神经切断术(n=9)或SAD加迷走神经切断术(n=4)前后，测定了α-氯醛糖麻醉犬PE过程中平均血压、平均肺动脉压(PAP)和肾交感神经活动(RSNA)的变化。PE使所有受试者的BP和PAP均升高。在SAB和CPR完好的狗，RSNA被反射性抑制(%变化RSNA：-76.3+/-4.7)。在SAD犬中，RSNA的抑制作用显著减弱，但未被取消(%改变RSNA：-27.5+/-11.8)。SAD后的这种抑制与PAP的升高密切相关。血压的微小变化(10毫米汞柱)与PAP和RSNA的变化不显著相关。SAD后容量扩张引起的PAP和RSNA的变化与PE的变化相似。选择性迷走神经切断术后，PE诱发的反射敏感性(%变化RSNA/mm-Hg变化BP)显著降低(-2.7±0.03比-1.8+/-0.12，P=0.01)。联合SAD和迷走神经切断术后，PE未能改变RSNA。我们的结论是，迷走神经心肺复苏有助于在PE期间抑制RSNA反射，但血压升高较小时除外。
Phenylephrine infusion (PE) has been used to raise arterial pressure (BP) in order to investigate reflex responses mediated by sinoaortic baroreflexes (SAB). Increases in cardiac filling pressures have been reported during PE. Our experiments determined whether PE selectively activates SAB without activation of vagal cardiopulmonary baroreflexes (CPR). We measured changes in mean BP, mean pulmonary arterial pressure (PAP), and renal sympathetic nerve activity (RSNA) during PE in alpha-chloralose-anesthetized dogs before and after sinoaortic denervation (SAD; n = 10), selective vagotomy (n = 9), or SAD and vagotomy (n = 4). PE elevated both BP and PAP in all dogs studied. In dogs with SAB and CPR intact, RSNA was reflexively inhibited (% change RSNA: -76.3 +/- 4.7). In SAD dogs, inhibition of RSNA was significantly attenuated but not abolished (% change RSNA: -27.5 +/- 11.8). This inhibition after SAD correlated closely with increases in PAP. Small BP changes (10 mmHg) were associated with insignificant changes in PAP and RSNA. Volume expansion after SAD produced changes in PAP and RSNA similar to those produced by PE. After selective vagotomy, the sensitivity (% change RSNA/mmHg change BP) of the reflex elicited by PE was significantly decreased (-2.7 +/- 0.03 pre vs. -1.8 +/- 0.12 post; P = 0.01). PE failed to change RSNA after combined SAD and vagotomy. We conclude that vagal CPR contribute to reflex inhibition of RSNA during PE except when elevations of BP are small.