L-精氨酸对体外循环中血管内皮细胞的保护效果

The protective effect of L-arginine on vascular endothelial cell during cardiopulmonary bypass

研究L-精氨酸（L-Arg）对体外循环（CPB）引起的血管内皮细胞激活/损伤的保护作用。方法 成年杂种犬12条,随机分为对照组（C组）和L-精氨酸组（L组）,每组6条。两组动物均摸拟临床开胸、建立体外循环心肌缺血再灌注过程。L组除转流前于静脉内注入L-Arg100mg·kg-1后,再持续静滴L-Arg10mg·kg-1·min-1至体外循环结束,余均同C组。分别于转前,转机5min,阻断主动脉15、45min,开放主动脉15、30min取静脉血,测血浆一氧化氮（NO）代谢产物（NO2-、NO3-）、丙二醛（MDA）、血管性假性血友病因子（vWF）水平,并于阻断15、45min及开放30min取股动脉及降主动脉标本做光镜检查,于转前、开放15、30min测体循环阻力（SVR）。结果 转机5min后的各时间段,L组的NO2、NO3水平显著高于C组,而血浆vWF水平及MDA水平显著低于C组;光镜检查C组各时间段血管内皮的破坏程度均比L组严重;L组SVR值显著低于C组。结论 CPB可致血管内皮细胞大量活化及严重损伤,内皮细胞功能障碍。左旋精氨酸可有效地保护CPB中血管内皮细胞免受损伤。

ve To assess the protective effect of L-arginine on vascular endothelial cell during cardiopulmonary bypass(CPB). Methods 12 adult healthy mongrel dogs of either sex weighing 10-15kg, were divided into L-arginine group (group L, n=6) and control group (group C, n=6) . Femoral artery and vein were cannulated for monitoring of MAP and CVP. Right internal jugular vein was cannulated with Swan-Ganz catheter for hemodynamic monitoring. L-arginine 100 mg·kg-1 was administered intravenously before CPB followed by continuous intravenous infusion at 10mg·kg-1.min-1 to the end of CPB in group L. Control group was treated as group L except the administration of L-arginine. Venous blood samples were taken before CPB, 5min after CPB was started, 15, 45min after aortic cross-clamping and 15, 30min after release of aortic cross-clamp for determination of the plasma levels of metabolites of nitric oxide (NO2- and NO3-), malondialdehyde (MDA) and von Willebrand Factor(vWF). Hemodynamic parameters were measured before CPB, 15 and 30min after release of aortic clamp. Specimens of tissue from femoral artery and descending aorta were taken for microscopic examination at 15,45 min after aortic cross-clamping and 30min after release of aortic cross-clamp.Results There was little difference in plasma NO2- and NO3-concentrations before CPB between the two groups. NO2- and NO3- levels increased significantly after CPB in both groups but were significantly higher in group L than those in group C (P<0.01). vWF and MDA levels were significantly lower in group L than those in group C. Distinct destruction of endothelial cells was found in group C by microscopic examination whereas the vascular endothelium was smooth and intact in group L. Systemic vascular resistance was lower in group L than that in group C.Conclusions Endothelial cells are seriously damaged during CPB and may be protected effectively with L-arginine.