Zhang T, Johns E J
Department of Physiology, The Medical School, Birmingham, United Kingdom.
Am J Physiol. 1997 Mar;272(3 Pt 2):R982-90. doi: 10.1152/ajpregu.1997.272.3.R982.
This study compared the cardiovascular and renal nerve activity responses to somatosensory stimulation with capsaicin in normotensive and hypertensive rats. The importance of the cardiopulmonary receptors in these two states was examined with the use of phenylbiguanide (PBG) infusion. Subcutaneous capsaicin increased blood pressure (BP), heart rate (HR), and renal nerve activity (RNA) 6-35% (P < 0.01), and total power (TP) and %power at HR (%PHR) rose two- to threefold (P < 0.001). PBG reduced basal RNA, TP, and %PHR (20-70%, P < 0.05). PBG did not change the cardiovascular, but attenuated the TP and %PHR increases due to capsaicin (P < 0.001-0.01). PBG given to vagotomized normotensive rats normalized the cardiovascular and RNA responses to capsaicin. In hypertensive rats, capsaicin increased BP, HR, RNA(10-20%), TP, and %PHR (50-70%, P < 0.001). PBG infusion into hypertensive rats decreased RNA (20%, P < 0.01) and the capsaicin-dependent rise in RNA was smaller (P < 0.05). TP and %PHR were unchanged, except in vagotomized hypertensive rats given PBG, in which these responses were minimally affected. Somatosensory modulation of RNA power spectra was suppressed by the cardiopulmonary receptors in normotensive rats, but in hypertensive rats their impact was much smaller.
本研究比较了正常血压和高血压大鼠对体感刺激与辣椒素的心血管和肾神经活动反应。通过使用苯双胍（PBG）输注来研究这两种状态下心肺感受器的重要性。皮下注射辣椒素使血压（BP）、心率（HR）和肾神经活动（RNA）升高6 - 35%（P < 0.01），总功率（TP）和心率百分比功率（%PHR）升高两到三倍（P < 0.001）。PBG降低了基础RNA、TP和%PHR（20 - 70%，P < 0.05）。PBG未改变心血管反应，但减弱了辣椒素引起的TP和%PHR升高（P < 0.001 - 0.01）。给迷走神经切断的正常血压大鼠注射PBG可使对辣椒素的心血管和RNA反应恢复正常。在高血压大鼠中，辣椒素使BP、HR、RNA升高（10 - 20%）、TP和%PHR升高（50 - 70%，P < 0.001）。给高血压大鼠输注PBG可降低RNA（20%，P < 0.01），且辣椒素依赖性的RNA升高幅度较小（P < 0.05）。TP和%PHR未改变，除了给迷走神经切断的高血压大鼠注射PBG时，这些反应受到的影响最小。在正常血压大鼠中，心肺感受器抑制了RNA功率谱的体感调制，但在高血压大鼠中其影响要小得多。
