Mauad H, Glass M L, Machado B H
Department of Physiology School of Medicine, University of São Paulo, Ribeirão Preto, Brazil.
Hypertension. 1992 Feb;19(2 Suppl):II182-6. doi: 10.1161/01.hyp.19.2_suppl.ii182.
Earlier studies report that sinoaortic baroreceptor denervation (SAD) in rats causes moderate elevation of mean arterial pressure along with a marked increase of arterial pressure lability (APL). In this context, we studied the effects of selective aortic denervation (AD) or selective carotid denervation (CD) on the regulation of blood pressure. In addition, we evaluated the effects of selective or total baroreceptor denervation on pulmonary ventilation and ventilation-related changes of arterial pressure. Mean arterial pressure was evaluated by computer-assisted techniques, and ventilation was measured by whole body plethysmography on conscious freely moving rats. With this approach, equal increases of mean arterial pressure were obtained for rats that had undergone AD, CD, and SAD. The APL was higher in SAD rats than in selectively denervated rats. CD and AD rats had an elevated APL relative to sham-operated animals, and its increase was approximately equal for the two selectively denervated groups. Total as well as selective denervation had relatively small effects on ventilation and on the general pattern of breathing. In all groups, this pattern consisted of regular ventilation, periodically interrupted by single deeper breaths. In SAD, AD, and CD animals, these larger tidal volumes were associated with marked transient reductions of mean arterial pressure, whereas small decreases of pressure occurred in sham-operated rats. The results indicate that both groups of baroreceptors must be present to keep mean arterial pressure at its normal level. Moreover, both receptor groups are equally important in reducing APL. Ventilation contributes to generation of APL after total or selective baroreceptor removal. Such ventilation-induced pressure changes are kept at a minimum in baroreceptor-intact rats.
早期研究报告称，大鼠的窦主动脉压力感受器去神经支配（SAD）会导致平均动脉压适度升高，同时动脉压变异性（APL）显著增加。在此背景下，我们研究了选择性主动脉去神经支配（AD）或选择性颈动脉去神经支配（CD）对血压调节的影响。此外，我们评估了选择性或完全压力感受器去神经支配对肺通气以及与通气相关的动脉压变化的影响。通过计算机辅助技术评估平均动脉压，通过全身体积描记法测量清醒自由活动大鼠的通气情况。采用这种方法，接受AD、CD和SAD的大鼠平均动脉压有同等程度的升高。SAD大鼠的APL高于选择性去神经支配的大鼠。与假手术动物相比，CD和AD大鼠的APL升高，且两个选择性去神经支配组的升高幅度大致相等。完全去神经支配以及选择性去神经支配对通气和呼吸的总体模式影响相对较小。在所有组中，这种模式包括规律的通气，偶尔被单次深呼吸打断。在SAD、AD和CD动物中，这些较大的潮气量与平均动脉压的显著短暂降低有关，而假手术大鼠的血压仅有小幅下降。结果表明，两组压力感受器都必须存在才能使平均动脉压维持在正常水平。此外，两组感受器在降低APL方面同样重要。在完全或选择性压力感受器切除后，通气会导致APL的产生。在压力感受器完整的大鼠中，这种通气诱导的压力变化保持在最低水平。
