Andreassen A K, Kvernebo K, Jørgensen B, Simonsen S, Kjekshus J, Gullestad L
Department of Cardiology, Rikshospitalet, Oslo, Norway.
Am Heart J. 1998 Aug;136(2):320-8. doi: 10.1053/hj.1998.v136.89731.
The aim of this study was to examine the responses to endothelium-dependent and -independent vasodilators on the peripheral microcirculation in heart transplant recipients in relation to exercise capacity compared with that in healthy controls.
Impaired endothelium-dependent vasodilation of the microcirculation may play an important role in the limitation of exercise capacity after heart transplantation.
Microvascular perfusion responses to four graded levels of iontophoretically applied 1% acetylcholine (endothelium-dependent vasodilator) and 1% sodium nitroprusside (SNP) (endothelium-independent) in the forearm skin of 42 transplant recipients and 16 age-matched controls were determined by laser Doppler perfusion measurements. Maximal exercise capacity was assessed by peak oxygen uptake (peak VO2) during progressive, symptom-limited, upright bicycle exercise.
With similar baseline perfusion levels in transplant recipients and controls (4.2 +/- 0.4 vs 4.6 +/- 0.6 arbitrary units [AU]), the increases in perfusion to acetylcholine, but not to SNP, were significantly attenuated in the transplant recipients: 7.0 +/- 1.0 vs 11.0 +/- 2.0, 12.7 +/- 1.5 vs 21.0 +/- 2.8, 21.0 +/- 1.9 vs 32.7 +/- 2.4, and 28.0 +/- 1.6 vs 39.2 +/- 2.4 AU, respectively (all p < 0.01). Peak VO2 was significantly lower in the transplant recipients (22.4 +/- 1.0 vs 38.0 +/- 2.9 ml/kg/min; p < 0.01). Furthermore, acetylcholine responses of the transplant recipients correlated closely to their peak VO2, irrespective of level of application (r = 0.63; p < 0.001, all four acetylcholine responses taken together), whereas no such correlation was found for SNP responses. In the control group, no relation was observed in acetylcholine/SNP responses to peak VO2.
Exercise limitation in transplant recipients appears strongly associated with attenuated endothelium-dependent vasodilation of the peripheral microcirculation.
本研究旨在探讨心脏移植受者外周微循环对内皮依赖性和非内皮依赖性血管舒张剂的反应，并与健康对照者相比，研究其与运动能力的关系。
微循环中内皮依赖性血管舒张功能受损可能在心脏移植后运动能力受限中起重要作用。
通过激光多普勒血流测量法，测定42例移植受者和16例年龄匹配对照者前臂皮肤对四个梯度水平的离子电渗法应用的1%乙酰胆碱（内皮依赖性血管舒张剂）和1%硝普钠（非内皮依赖性）的微血管灌注反应。通过进行性、症状限制的直立自行车运动期间的峰值摄氧量（峰值VO₂）评估最大运动能力。
移植受者和对照者的基线灌注水平相似（4.2±0.4对4.6±0.6任意单位[AU]），移植受者对乙酰胆碱而非硝普钠的灌注增加明显减弱：分别为7.0±1.（此处原文有误，应为7.0±1.0）对11.0±2.0、12.7±1.5对21.0±2.8、21.0±1.9对32.7±2.4以及28.0±1.6对39.2±2.4 AU（均p<0.01）。移植受者的峰值VO₂明显较低（22.4±1.0对38.0±2.9 ml/kg/min；p<0.01）。此外，移植受者对乙酰胆碱的反应与其峰值VO₂密切相关，无论应用水平如何（r = 0.63；p<0.001，四个乙酰胆碱反应综合考虑），而硝普钠反应未发现这种相关性。在对照组中，未观察到乙酰胆碱/硝普钠反应与峰值VO₂之间的关系。
移植受者的运动受限似乎与外周微循环中内皮依赖性血管舒张减弱密切相关。
