高血压患者与正常血压者皮肤微血管对乙酰胆碱和硝普钠反应性比较

Cutaneous Vascular Responses to Acetylcholine and Sodium Nitroprusside in Hypertensive Patients and Normotensive Subjects

目的 内皮细胞功能是目前研究的热点 ,本研究用离子电渗透法比较了高血压患者和正常血压者内皮细胞功能和血管舒张功能。方法 33例原发性高血压患者和 2 3例正常血压者志愿参加试验。将 1%硝普钠用离子电渗透法导入左前臂掌侧皮肤 ,皮肤血管则产生非内皮细胞依赖的血管舒张。将 1%乙酰胆碱用离子电渗透法导入左前臂掌侧皮肤 ,皮肤血管则产生内皮细胞依赖的血管舒张。血管流导 (VC)计算依照公式 :VC =皮肤血流 / (舒张压 +脉压差 / 3)。结果 高血压患者硝普钠和乙酰胆碱离子电渗透法测定皮肤血管流导分别为 1.17± 0 36PU/mmHg和 0 75± 0 2 9PU/mmHg ,正常血压组两项值分别为 1.38± 0 2 7PU/mmHg和 1.0 7± 0 2 3PU/mmHg ,高血压患者皮肤微血管对硝普钠和乙酰胆碱的反应性较正常血压组均显著下降 (P <0 0 5 )。高血压组乙酰胆碱流导峰值和硝普钠流导峰值分别较正常血压组下降 30 4± 2 8.2 %和 15 .4± 2 6 .6 % ,前者下降幅度大于后者 (P <0 0 1)。结论 高血压患者存在皮肤微血管内皮细胞功能障碍和血管平滑肌舒张功能障碍 ,并以内皮细胞功能障碍为主。

Objective Impaired function of the vascular endothelium has been well documented in hypertension. The aim of the present study was to establish a non invasive technique of transdermal drug iontophoresis to assess cutaneous endothelial function in hypertensive patients. Methods In 33 hypertensive and 23 normotensive volunteers, we delivered acetylcholine (ACh), an endothelium dependent vasodilator, and sodium nitroprusside (SNP), an endothelium independent vasodilator, to dermal vessels of the forearm using iontophoresis, and measured vasodilatation (laser Doppler blood flow, LDF) using laser Doppler fluximetry. Brachial artery blood pressure was measured by cuff sphygmomanometry manually. Mean artery pressure (MAP) was calculated as MAP=diastolic pressure + (systolic pressure\|diastolic pressure)/3. Forearm cutaneous vascular conductance (CVC) was calculated as CVC = LDF / MAP. Results CVC in the normotensive subjects was 1.38±0 27 PU/mmHg and 1.07±0 23 PU/mmHg for SNP and ACh. CVC in the hypertensive patients was 1.17±0 36 PU/mmHg and 0 75±0 29 PU/mmHg for SNP and ACh, which was significantly lower than in the normotensive group ( P <0 05). Conclusion These data suggest that endothelial function and vascular relaxation capacity may be impaired in the skin microcirculation of hypertensive patients.