Walsh G M
Clin Exp Hypertens A. 1983;5(4):577-601. doi: 10.3109/10641968309081794.
Systemic vascular responsiveness to i.v. bolus injections of norepinephrine and tyramine was evaluated in adult male spontaneously hypertensive rats (SHR) and normotensive Wistar-Kyoto rats (WKY). Changes in total peripheral resistance (TPR) were used as an index of vascular response. Dose-response curves were plotted with 1n-dose on the x-axis and percent of maximum change in TPR on the y-axis, and the following indices of responsiveness were used: slope, 1nED50, 1nx-intercept, and maximum response. Measurements were made before and after ganglionic blockade with pentolinium (5 mg/kg, i.v.). Cardiac output for TPR calculations was obtained from an implanted flow probe on the ascending aorta. The slopes and maximum responses to norepinephrine and tyramine were greater in SHR v. WKY, P less than .05, before and after pentolinium treatment. There were no significant differences in 1nED50 or 1nx-intercept between WKY and SHR for tyramine and norepinephrine prior to pentolinium. After pentolinium 1nED50 and 1nx-intercept were similar for SHR and WKY for norepinephrine, but were greater in SHR for tyramine. The results demonstrate an increased systemic vascular responsiveness to catecholamines in adult SHR, with no evidence of increased systemic vascular sensitivity. These findings are consistent with the concept of increased systemic vascular responsiveness to catecholamines in adult SHR secondary to structural changes in blood vessels.
在成年雄性自发性高血压大鼠（SHR）和正常血压的Wistar-Kyoto大鼠（WKY）中评估了静脉推注去甲肾上腺素和酪胺后全身血管反应性。总外周阻力（TPR）的变化用作血管反应的指标。以x轴上的1n剂量和y轴上TPR最大变化百分比绘制剂量-反应曲线，并使用以下反应性指标：斜率、1nED50、1nx截距和最大反应。在用潘托铵（5mg/kg，静脉注射）进行神经节阻断前后进行测量。计算TPR时的心输出量由植入升主动脉的流量探头获得。在潘托铵治疗前后，SHR对去甲肾上腺素和酪胺的斜率和最大反应均高于WKY，P<0.05。在潘托铵治疗前，WKY和SHR对酪胺和去甲肾上腺素的1nED50或1nx截距无显著差异。潘托铵治疗后，SHR和WKY对去甲肾上腺素的1nED50和1nx截距相似，但SHR对酪胺的1nED50和1nx截距更大。结果表明成年SHR对儿茶酚胺的全身血管反应性增加，且无全身血管敏感性增加的证据。这些发现与成年SHR因血管结构变化继发的对儿茶酚胺的全身血管反应性增加的概念一致。
