体外循环期间内源性NO水平的研究

目的　探讨体外循环对血管内皮依赖性舒张功能的影响及与肺动脉高压的关系。方法　 2 0例置换双瓣病人 ,按术前肺动脉压分成二组 :肺高压组 (H)和正常组 (N) ,在体外循环前、体外循环后即刻及体外后 4、12h测基础状态、静注乙酰胆碱 (Ach)后和吸一氧化氮 (NO)w =2 0× 10 -6时的环鸟苷酸 (cGMP)水平。结果　体外循环使cGMP下降 ,12h后回升 ,以H组为明显 ;注射Ach及吸入NO都引起cGMP增加 ;N组cGMP水平受体外循环影响较H组轻 (分别为 12 .16～ 17.2 0和 4.45～ 13.73pmol/ml) ,而且吸入NO的影响较静注Ach影响更大。结论　伴肺高压的心瓣膜病患者血管内皮功能已处于减弱状态 ,其程度比正常肺动脉压者重 ,体外循环造成的血管内皮功能损伤在肺高压患者更为突出。

Study of Intrinsic NO Levels during Cardiopulmonary Bypass

Purpose To study the impacts of cardiopulmonary bypass (CPB) on vascular endothelium-de-pendent relaxation and the relations of CPB and pulmonary hypertension. Methods Twenty valvular replacing patients were tested. According to their preoperative pulmonary arterial pressure (PAP), these patients divided into pulmonary hypertension group (H) and normal group (N). Measure the concentrations of cGMP of basic condition, after acetylcholine(Ach) intravenation and during nitric oxide (NO) inhalation before the sternal split, after weaning from CPB immediately, the 4 hour and the 12 hour later. Results It was found that the concentrations of cGMP declined during CPB and resumed 12 hour after, especially in the H group Ach intravenation and NO inhalation increased releasing of cGMP, and level of cGMP was less influen-ced by CPB in the N group than in the H group ( 12.16～17.12 and 4.45～13.73 pmol/ml respectively). It was also found that NO inhalation had more effects than Ach intravenation. Conclusions We concluded that the injury of vascular endothelium function caused by CPB was more critical in pulmonary hypertension patients.