Rosei E A, Rizzoni D, Castellano M, Porteri E, Zulli R, Muiesan M L, Bettoni G, Salvetti M, Muiesan P, Giulini S M
Semeiotica and Metodologia Medica, University of Brescia, Italy.
J Hypertens. 1995 Mar;13(3):341-7.
For the evaluation in humans of structural alterations in resistance arteries, most studies have used an indirect index, the measurement of minimal vascular resistance (mean blood pressure divided by maximal postischaemic blood flow) in suitable vascular beds. A sensitive and specific micromyographic technique was recently made available for the study of human small resistance arteries. Whether a correlation really exists between results obtained with the two techniques has not yet been investigated.
To evaluate both forearm minimal vascular resistance and media:lumen ratio of omental or subcutaneous small arteries in normotensive subjects and hypertensive patients.
Thirty-four individuals were included in the study (age range 35-74 years; 24 hypertensive, 10 normotensive). Twenty-five had elective abdominal surgery and nine hypertensive patients had a gluteal biopsy. Omental and subcutaneous small arteries were dissected and mounted on a wire micromyograph (Mulvany's technique), and media:lumen ratio and media thickness were measured. The dose-response curve to noradrenaline was constructed at cumulative concentrations from 3 x 10(-9) to 3 x 10(-5) mol/l. Venous occlusion plethysmography was used to measure blood flow in the forearm, and minimal vascular resistance was calculated from mean blood pressure and postischaemic maximal blood flow (13 min ischaemia plus exercise).
A statistically significant correlation was found between media:lumen ratio and minimal vascular resistance (r = 0.74, P < 0.001) as well as between media:lumen ratio and systolic (r = 0.44, P < 0.01) and diastolic (r = 0.38, P < 0.05) blood pressures. Similar correlations were observed between media thickness and systolic and diastolic blood pressures. Small arteries from hypertensive patients had a significantly increased reactivity to noradrenaline (by analysis of variance) compared with those from normotensive subjects, in terms of wall tension but not of active media stress.
The present study demonstrated that the media:lumen ratio of small resistance vessels is significantly related to forearm minimal vascular resistance, suggesting that direct and indirect evaluations of vascular morphology will give similar results.
在人体中评估阻力动脉的结构改变时，大多数研究使用的是间接指标，即测量合适血管床的最小血管阻力（平均血压除以缺血后最大血流量）。最近出现了一种灵敏且特异的微血管造影技术，可用于研究人体小阻力动脉。这两种技术所获结果之间是否真的存在相关性尚未得到研究。
评估正常血压受试者和高血压患者的前臂最小血管阻力以及网膜或皮下小动脉的中膜与管腔比值。
34人纳入本研究（年龄范围35 - 74岁；24名高血压患者，10名正常血压受试者）。25人接受择期腹部手术，9名高血压患者接受臀肌活检。解剖网膜和皮下小动脉并安装在钢丝微血管造影仪上（穆尔瓦尼技术），测量中膜与管腔比值和中膜厚度。构建去甲肾上腺素在3×10⁻⁹至3×10⁻⁵mol/L累积浓度下的剂量 - 反应曲线。采用静脉阻断体积描记法测量前臂血流量，并根据平均血压和缺血后最大血流量（缺血13分钟加运动）计算最小血管阻力。
中膜与管腔比值和最小血管阻力之间存在显著的统计学相关性（r = 0.74，P < 0.001），中膜与管腔比值和收缩压（r = 0.44，P < 0.01）及舒张压（r = 0.38，P < 0.05）之间也存在显著的统计学相关性。中膜厚度与收缩压和舒张压之间也观察到类似的相关性。与正常血压受试者的小动脉相比，高血压患者的小动脉对去甲肾上腺素的反应性在壁张力方面显著增加（通过方差分析），但在活性中膜应力方面无显著增加。
本研究表明，小阻力血管的中膜与管腔比值与前臂最小血管阻力显著相关，提示对血管形态的直接和间接评估将得出相似的结果。
