Wright C E, Angus J A, Korner P I
Hypertension. 1987 Feb;9(2):122-31. doi: 10.1161/01.hyp.9.2.122.
The local responses of the resistance vessels of the hindquarters of conscious, renal hypertensive (cellophane wrap) and sham-operated normotensive rabbits were studied during infusions of constrictor (norepinephrine, methoxamine, angiotensin II) and dilator (acetylcholine, adenosine, serotonin) drugs. The rabbits had implanted Doppler ultrasonic flow probes on the lower aorta and an indwelling catheter for intra-arterial infusion of drugs. Autonomic blockade with mecamylamine and propranolol was used to determine local vascular effects of each drug uncomplicated by reflex changes. Logistic dose-vascular response curves were characterized by their range from resting to maximum response, their 50% effective dose (i.e., sensitivity or dose at middle of the response range), and the average slope about the 50% effective dose. At maximum dilatation the vascular resistance was about 70% greater in hypertensive rabbits than in normotensive rabbits. There were no significant differences in 50% effective dose values between curves for hypertensive and normotensive rabbits for constrictor or dilator drugs. However, with all drugs the hypertensive rabbits showed about twice the change in vascular resistance per unit dose compared with the normotensive rabbits. These results suggest that hypertrophy of the muscles of the precapillary vessels makes them a nonspecific amplifier of vascular resistance changes evoked by constrictor and dilator stimuli. They do not support previous claims of specific changes in "sensitivity" or claims that local amplifier action is unimportant in hypertension.
在清醒的肾性高血压（玻璃纸包裹法）兔和假手术对照的正常血压兔的后肢阻力血管局部反应研究中，输注了缩血管药物（去甲肾上腺素、甲氧明、血管紧张素II）和扩血管药物（乙酰胆碱、腺苷、5-羟色胺）。这些兔子在腹主动脉下段植入了多普勒超声血流探头，并留置了一根动脉内给药导管。使用美加明和普萘洛尔进行自主神经阻滞，以确定每种药物的局部血管效应，而不受反射变化的干扰。逻辑剂量-血管反应曲线的特征在于其从静息到最大反应的范围、其50%有效剂量（即反应范围中间的敏感性或剂量）以及围绕50%有效剂量的平均斜率。在最大扩张时，高血压兔的血管阻力比正常血压兔大约高70%。对于缩血管或扩血管药物，高血压兔和正常血压兔的曲线在50%有效剂量值方面没有显著差异。然而，对于所有药物，高血压兔每单位剂量的血管阻力变化约为正常血压兔的两倍。这些结果表明，毛细血管前血管的肌肉肥大使其成为由缩血管和扩血管刺激引起的血管阻力变化的非特异性放大器。它们不支持先前关于“敏感性”有特定变化的说法，也不支持局部放大器作用在高血压中不重要的说法。
