Cross K S, Davies M G, el-Sanadiki M N, Murray J J, Mikat E M, Hagen P O
Department of Surgery, Duke University Medical Center, Durham, North Carolina 27710.
Br J Surg. 1994 May;81(5):699-705. doi: 10.1002/bjs.1800810524.
Vasoreactivity of 11 coronary artery vein bypass grafts and 13 human saphenous veins was examined. Isometric tension studies were performed in response to potassium chloride (110 mmol/l), noradrenaline (10(-9)-10(-4) mol/l), serotonin (10(-9)-10(-4) mol/l) and histamine (10(-8)-10(-2) mol/l). After precontraction with noradrenaline (10(-5) mol/l), the response to acetylcholine (10(-8)-10(-4) mol/l) and the calcium ionophore A23187 (10(-8)-10(-4) mol/l) was also assessed. Results are given as mean(s.e.m.). Compared with saphenous veins, vein grafts showed decreased sensitivity to noradrenaline (1.7(0.5) versus 0.4(0.1) mumol/l, P = 0.01), no change in sensitivity to serotonin (55(18) versus 37(15) mumol/l, P > 0.05) and supersensitivity to histamine (3.2(0.9) versus 30.1(13.2) mumol/l, P = 0.01). Vein grafts had a decreased maximal contraction to potassium chloride (1.1(0.3) versus 5.5(0.8) g, P = 0.0001), noradrenaline (1.2(0.3) versus 4.1(0.8) g, P = 0.005), histamine (1.2(0.3) versus 4.5(0.8) g, P = 0.003) and serotonin (0.7(0.2) versus 5.7(0.6) g, P = 0.0002) compared with saphenous vein. Precontracted vein grafts did not relax in response to acetylcholine; in contrast, saphenous vein relaxed in a dose-dependent manner to a maximal relaxation of 22(3) per cent. Both saphenous vein and vein graft relaxed in response to A23187. Vein graft intimal thickness was approximately fourfold greater than that of saphenous vein (540(110) versus 136(30) microns). Scanning electron microscopy of vein and vein graft revealed an intact endothelium. Coronary artery vein grafts are capable of responding to various contractile agonists; these response are notably different from those of saphenous vein and there is a loss of endothelium-dependent relaxation. Even at a late stage vein grafts are not inert but are functional conduits with an abnormally responsive endothelium and a less potent, but significantly altered, smooth muscle contractile profile.
检测了11条冠状动脉静脉搭桥血管和13条人隐静脉的血管反应性。进行等长张力研究，以观察对氯化钾（110 mmol/l）、去甲肾上腺素（10⁻⁹ - 10⁻⁴ mol/l）、5-羟色胺（10⁻⁹ - 10⁻⁴ mol/l）和组胺（10⁻⁸ - 10⁻² mol/l）的反应。在用去甲肾上腺素（10⁻⁵ mol/l）预收缩后，还评估了对乙酰胆碱（10⁻⁸ - 第十⁻⁴ mol/l）和钙离子载体A23187（10⁻⁸ - 10⁻⁴ mol/l）的反应。结果以平均值（标准误）表示。与隐静脉相比，静脉搭桥血管对去甲肾上腺素的敏感性降低（1.7(0.5) 对0.4(0.1) μmol/l，P = 0.01），对5-羟色胺的敏感性无变化（55(18) 对37(15) μmol/l，P > 0.05），对组胺超敏（3.2(0.9) 对30.1(13.2) μmol/l，P = 0.01）。静脉搭桥血管对氯化钾（1.1(0.3) 对5.5(0.8) g，P = 0.0001）、去甲肾上腺素（1.2(0.3) 对4.1(0.8) g，P = 0.005）、组胺（1.2(0.3) 对4.5(0.8) g，P = 0.003）和5-羟色胺（0.7(0.2) 对5.7(0.6) g，P = 0.0002）的最大收缩力均低于隐静脉。预收缩的静脉搭桥血管对乙酰胆碱无舒张反应；相反，隐静脉以剂量依赖方式舒张，最大舒张率为22(3)%。隐静脉和静脉搭桥血管对A23187均有舒张反应。静脉搭桥血管内膜厚度约为隐静脉的四倍（540(110) 对136(30) 微米）。静脉和静脉搭桥血管的扫描电子显微镜检查显示内皮完整。冠状动脉静脉搭桥血管能够对多种收缩激动剂产生反应；这些反应与隐静脉明显不同，且存在内皮依赖性舒张功能丧失。即使在晚期，静脉搭桥血管也并非无活性，而是具有功能的管道，其内皮反应异常，平滑肌收缩特性减弱但明显改变。
