Makita S, Nakamura M, Murakami H, Komoda K, Kawazoe K, Hiramori K
Second Department of Internal Medicine, Iwate Medical University, Japan.
Circulation. 1996 Nov 1;94(9 Suppl):II211-5.
Thromboangiitis obliterans (TAO) is an occlusive arterial disease and a separate disease entity from atherosclerosis. It occurs mainly in the small and medium-sized vessels. Although the cause of TAO is unknown, systemic factors (immunological or humoral) may be involved in addition to abnormal peripheral microcirculation. Endothelium is now recognized as an important factor in the maintenance of microvascular circulation and the inhibition of platelet aggregation. This study examines the possible impairment of endothelium-dependent vasodilation in the peripheral vasculature of patients with TAO.
Forearm blood flow (FBF) changes induced by the endothelium-dependent vasodilator acetylcholine, the endothelium-independent vasodilator sodium nitroprusside, and occlusion-induced reactive hyperemia were measured plethysmographically in eight patients with TAO and in eight healthy control subjects matched for age and smoking status. The increase in FBF response to intra-arterial acetylcholine infusion was lower in patients with TAO than in healthy control subjects (peak FBF, 22.9 +/- 2.9 versus 14.1 +/- 2.8 mL/min per dL of tissue volume; P < .01). In contrast, there was no significant difference in the increase in FBF response to sodium nitroprusside infusion between the two groups (peak FBF 13.1 +/- 4.0 versus 16.3 +/- 2.5 mL/min per dL of tissue volume; P = NS). In the case of reactive hyperemia, there were no significant differences between the two groups at any time points of hyperemia (peak FBF, 32.9 +/- 4.0 versus 31.4 +/- 3.3 mL/min per dL of tissue volume; P = NS).
These results indicate that peripheral endothelium-dependent vasodilation is impaired in the nondiseased limb of patients with TAO. This type of vascular dysfunction may contribute to such characteristics as segmental proliferative lesion and thrombus formation in the peripheral vessels of patients with TAO.
血栓闭塞性脉管炎（TAO）是一种闭塞性动脉疾病，与动脉粥样硬化是不同的疾病实体。它主要发生在中小血管。虽然TAO的病因尚不清楚，但除了外周微循环异常外，全身因素（免疫或体液因素）可能也参与其中。现在认为内皮是维持微血管循环和抑制血小板聚集的重要因素。本研究探讨TAO患者外周血管中内皮依赖性血管舒张功能可能存在的损害。
采用体积描记法测量8例TAO患者和8例年龄及吸烟状况相匹配的健康对照者，经内皮依赖性血管舒张剂乙酰胆碱、非内皮依赖性血管舒张剂硝普钠诱导的前臂血流量（FBF）变化以及闭塞诱导的反应性充血。TAO患者对动脉内注入乙酰胆碱的FBF反应增加低于健康对照者（每dL组织体积的峰值FBF，22.9±2.9对14.1±2.8 mL/min；P<0.01）。相比之下，两组对硝普钠注入的FBF反应增加无显著差异（每dL组织体积的峰值FBF 13.1±4.0对16.3±2.5 mL/min；P=无显著性差异）。在反应性充血的情况下，两组在充血的任何时间点均无显著差异（每dL组织体积的峰值FBF，32.9±4.0对31.4±3.3 mL/min；P=无显著性差异）。
这些结果表明，TAO患者未患病肢体的外周内皮依赖性血管舒张功能受损。这种血管功能障碍可能导致TAO患者外周血管出现节段性增殖性病变和血栓形成等特征。
