Osborn J W, England S K
Department of Veterinary Biology, University of Minnesota, St. Paul 55108.
Am J Physiol. 1990 Dec;259(6 Pt 2):R1172-80. doi: 10.1152/ajpregu.1990.259.6.R1172.
Studies in several species have demonstrated that mean arterial pressure (MAP) is normal or only slightly elevated after chronic arterial baroreceptor denervation. We hypothesized that the absence of sustained hypertension after barodenervation was the result of a pressure natriuresis response, secondary to sympathetic vasoconstriction of nonrenal vasculature. To test this hypothesis, MAP, sodium balance (NaBal), and water balance were measured before and after aortic baroreceptor denervation (ABD), sinoaortic denervation (SAD), or sham surgery in conscious rats. MAP was increased 20.0 +/- 3.7 mmHg 1 day after ABD but returned to control by day 3. ABD had no significant effect on daily NaBal or water balance. The responses to SAD were similar to those after ABD, with the exception that a significant natriuresis was observed the first day after SAD. However, this was followed by a significant antinatriuresis on day 2, when MAP was still elevated. By day 3 after SAD, MAP, NaBal, and water balance were not significantly different from control. These results suggest that the normalization of MAP after ABD or SAD is not the result of pressure natriuresis but rather failure to maintain a chronic elevation of sympathetic activity after barodenervation.
对多个物种的研究表明，慢性动脉压力感受器去神经支配后，平均动脉压（MAP）正常或仅略有升高。我们推测，压力感受器去神经支配后未出现持续性高血压是压力性利钠反应的结果，该反应继发于非肾血管系统的交感神经血管收缩。为验证这一假设，在清醒大鼠中，于主动脉压力感受器去神经支配（ABD）、窦主动脉去神经支配（SAD）或假手术后，测量MAP、钠平衡（NaBal）和水平衡。ABD后1天，MAP升高20.0±3.7 mmHg，但在第3天恢复至对照水平。ABD对每日NaBal或水平衡无显著影响。对SAD的反应与ABD后相似，不同之处在于SAD后第一天观察到显著的利钠作用。然而，随后在第2天出现显著的钠潴留，此时MAP仍升高。SAD后第3天，MAP、NaBal和水平衡与对照无显著差异。这些结果表明，ABD或SAD后MAP恢复正常并非压力性利钠的结果，而是压力感受器去神经支配后未能维持交感神经活动的慢性升高。
