Sympathetic activation restrains endothelium-mediated muscle vasodilatation in heart failure patients
Sympathetic activation restrains endothelium-mediated muscle vasodilatation in heart failure patients
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DOI：
10.1152/ajpheart.01240.2004
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发表时间：
2005-08-01
影响因子：
4.8
通讯作者：
Negrao, CE
中科院分区：
文献类型：
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作者：
Santos, AC;Alves, MJNN;Negrao, CE
虽然心力衰竭（HF）患者在精神压力下的血管舒张反应减弱，但这种现象的机制尚未完全了解。我们检验了慢性心力衰竭患者在精神应激时交感神经活动限制内皮依赖性血管舒张的假设。21例HF患者（年龄45 +/-2岁，功能分级III和IV，纽约心脏协会）和22名年龄匹配的正常对照（NC;年龄42 +/- 2岁，P = 0.13）在休息时和4分钟Stroop色字试验期间用肱动脉内盐水、乙酰胆碱（内皮依赖性）、酚妥拉明（α-阻断剂）和酚妥拉明加乙酰胆碱输注。前臂血流量通过静脉闭塞体积描记法测量。HF患者的基线前臂血管传导性（FVC）显著较低（2.18 +/- 0.12 vs. 3.66 +/- 0.22单位，P = 0.001）。在使用生理盐水的精神应激期间，HF患者的FVC变化与NC相比显著减弱（0.92 +/- 0.20 vs. 2.13 +/- 0.39单位，P = 0.001）。在HF中，乙酰胆碱的血管舒张作用与生理盐水对照相似，但显著低于NC。在HF患者中，酚妥拉明显著增加FVC反应（1.16 +/- 0.20 vs. 2.09 +/- 0.29单位，P = 0.001），HF患者与NC之间的差异趋于减小（2.09 +/- 0.29 vs. 3.61 +/- 0.74单位，P = 0.052）。酚妥拉明加乙酰胆碱的血管舒张作用在HF和NC之间相似（4.23 +/- 0.73 vs. 4.76 +/- 1.03单位，P = 0.84）。总之，交感神经激活介导心力衰竭患者在精神应激时肌肉内皮细胞介导的血管舒张功能减弱。
Although the vasodilatory response during mental stress is blunted in heart failure (HF), the mechanisms underlying this phenomenon are not fully understood. We tested the hypothesis that sympathetic activity limits the endothelium-dependent vasodilatation during mental stress in chronic HF patients. Twenty-one HF patients ( age 45 +/- 2 yr, functional classes III and IV, New York Heart Asssociation) and 22 age-matched normal controls (NC; age 42 +/- 2 yr, P = 0.13) were studied at rest and during 4 min of Stroop color-word test with brachial intra-arterial saline, acetylcholine ( endothelium dependent), phentolamine ( alpha-blocker), and phentolamine plus acetylcholine infusion. Forearm blood flow was measured by venous occlusion plethysmography. Baseline forearm vascular conductance (FVC) was significantly lower in HF patients (2.18 +/- 0.12 vs. 3.66 +/- 0.22 units, P = 0.001). During mental stress with saline, the changes in FVC were significantly blunted in HF patients compared with NC (0.92 +/- 0.20 vs. 2.13 +/- 0.39 units, P = 0.001). In HF, the vasodilatation with acetylcholine was similar to saline control and significantly lower than in NC. In HF patients, phentolamine significantly increased FVC responses ( 1.16 +/- 0.20 vs. 2.09 +/- 0.29 units, P = 0.001), and the difference between HF patients and NC tended to decrease (2.09 +/- 0.29 vs. 3.61 +/- 0.74 units, P = 0.052). The vasodilatation with phentolamine plus acetylcholine was similar between HF and NC (4.23 +/- 0.73 vs. 4.76 +/- 1.03 units, P = 0.84). In conclusion, sympathetic activation mediates the blunted muscle endothelium-mediated vasodilatation during mental stress in HF patients.