Gregory L C, Quillen E W, Keil L C, Chang D, Reid I A
Department of Physiology, University of California, San Francisco 94143.
Am J Physiol. 1988 Apr;254(4 Pt 1):E490-5. doi: 10.1152/ajpendo.1988.254.4.E490.
Previous studies have provided evidence that vasopressin plays an important role in blood pressure regulation during water deprivation. However, these investigations have been complicated by reflex compensatory increases in cardiac output and renin secretion. The aim of the present study was to investigate the effect of blockade of the vasoconstrictor action of vasopressin in conscious water-deprived dogs in which the low- and/or high-pressure baroreceptors were denervated to minimize reflex responses. Vasopressin blockade in sham-operated dogs (n = 7) did not change arterial pressure. Heart rate rose from 78 +/- 9 to 119 +/- 13 beats/min (P less than 0.01), and plasma renin activity increased from 10.9 +/- 2.1 to 21.6 +/- 4.6 ng.ml-1.3 h-1 (P less than 0.01). In carotid sinus-denervated dogs (n = 6), vasopressin blockade again failed to decrease arterial pressure. Heart rate increased from 105 +/- 10 to 132 +/- 10 beats/min (P less than 0.01), and plasma renin activity rose from 6.8 +/- 1.7 to 15.5 +/- 2.4 ng.ml-1.3 h-1 (P less than 0.01). The antagonist also failed to change blood pressure in cardiac-denervated dogs (n = 5). Heart rate increased from 111 +/- 9 to 119 +/- 1 beats/min (P less than 0.01), but plasma renin activity did not increase significantly. In marked contrast, vasopressin blockade in sinoaortic/cardiac-denervated dogs (n = 7) promptly decreased arterial pressure from 115 +/- 8 to 94 +/- 7 mmHg (P less than 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)
先前的研究已提供证据表明，血管加压素在缺水期间的血压调节中起重要作用。然而，这些研究因心输出量和肾素分泌的反射性代偿性增加而变得复杂。本研究的目的是探讨在清醒的缺水犬中阻断血管加压素的血管收缩作用的效果，这些犬的低压和/或高压压力感受器已去神经支配，以尽量减少反射反应。假手术犬（n = 7）中血管加压素阻断未改变动脉血压。心率从78±9次/分钟升至119±13次/分钟（P<0.01），血浆肾素活性从10.9±2.1 ng·ml⁻¹·3 h⁻¹增至21.6±4.6 ng·ml⁻¹·3 h⁻¹（P<0.01）。在颈动脉窦去神经支配的犬（n = 6）中，血管加压素阻断再次未能降低动脉血压。心率从105±10次/分钟增至132±10次/分钟（P<0.01），血浆肾素活性从6.8±1.7 ng·ml⁻¹·3 h⁻¹升至15.5±2.4 ng·ml⁻¹·3 h⁻¹（P<0.01）。拮抗剂在心脏去神经支配的犬（n = 5）中也未能改变血压。心率从111±9次/分钟增至119±1次/分钟（P<0.01），但血浆肾素活性未显著增加。与之形成鲜明对比的是，在窦主动脉/心脏去神经支配的犬（n = 7）中，血管加压素阻断迅速将动脉血压从115±8 mmHg降至94±7 mmHg（P<0.01）。（摘要截短于250字）
