Development of Measuring System of Endothelium-Derived Relaxing Factor(NO)and Vascular Luminal Shear Stress

1.离体大鼠心脏：采用NO微电极（100 μ m; 1 pA [] s .apprxeq.）测定离体大鼠心脏（Langendorff模式灌注）肺动脉排出的冠状动脉灌注液中的NO浓度。[) 1.5 nM NO)。冠状动脉灌注液中NO浓度随灌注压升高而升高[47]。[1]李建平，李建平，李建平，等。40cm H下6pa <@D22@>D2O,69(][1]张建军，张建军，张建军，等。10pa温度下70cmh <@D22@>D2O,99(][] 17 pA在100 cmH<@D22@>D2O)。缺血1 min后，NO浓度在再灌注时出现短暂性峰值，缺血10 min后，开始出现短暂性小峰值，随后逐渐升高（达到peudo-steady值）[22]。[)3 pA 1 min vs 124(]SY.+-。[)17 pA, 10 min)。这些结果似乎反映了缺血过程中积累的NO的冲刷以及再灌注过程中剪切应力的增加作用。人工血管：两种类型的人工血管（Terumo的PF-V和Gore的ePTFE，均为10 cm长）通过连接股动脉植入狗体内。一定时间后，分离各组血管，测定内皮细胞一氧化氮的生成。1 mM l -精氨酸灌注与100 muM L-NA灌注后NO电流测量差异如下：2周后（PF-V: 52 pA、49 pA）、1个月后（PF-V: 45 pA、ePTFE: 233 pA）、12个月后（无显著变化）、13个月后（无显著变化）。这些结果表明，在短时间内，血管腔侧形成的新内膜具有生成NO的能力，但在长时间（约1年）后，内皮细胞认识到NO生成的生理功能是不必要的，从而可能导致NO合成酶活性和/或NO合成酶数量的下降。内皮细胞产生一氧化氮与抗血栓性直接相关，因此在这方面，新内膜的抗血栓能力可能在长时间后减弱。少

1.Isolated Rat Hearts : NO concentration in the coronary perfusate ejected from the pulmonary artery of isolated rat hearts(perfused in Langendorff mode) was measured using an NO microelectrode (100 mum ; 1 pA (]SY.apprxeq.[) 1.5 nM NO). NO concentration in the coronary perfusate increased with increasing perfusion pressure (47(]SY.+-。[)6 pA at 40cm H<@D22@>D2O,69(]SY.+-。[)10 pA at 70 cmH<@D22@>D2O,99(]SY.+-。[)17 pA at 100 cmH<@D22@>D2O). After 1-min ischemia, a transient peak of NO concentration was observed during reperfusion, and after 10-min ischemia, a transient small peak appeared initially followed by a gradual increase (reaching a peudo-steady value)was observed (22(]SY.+-。[)3 pA for 1 min vs 124(]SY.+-。[)17 pA for 10 min). These results seem to reflect the washout of accumulated NO during ischemia as well as the increasing effect of shear stress during reperfusion.2. Artificial Vessels : Two types of artificial vessels (PF-V of Terumo and ePTFE of Gore ; both 10 cm long) were … More implanted in dogs by connecting to the femoral arteries. After a certain period, each vessel was isolated, and NO production from the endothelium was measured. The differences of measured NO currents between 1 mM L-arginine and 100 muM L-NA perfusions were as follows : after 2 weeks (PF-V : 52 pA,49 pA), after 1 month(PF-V : 45 pA,ePTFE : 233 pA), after 12 months(no significant change), and after 13 months(no significant change). These results imply that the neo-intima formed on the luminal side of each vessel has ability of NO production after a short-implantation period but after long duration(about 1 year), the endothelium recognizes the physiological function of NO production to be unnecessary, thus perhaps resulting in the decrease in NO synthase activity and/or the number of NO synthase. NO production from the endothelium is directly related with the antithrombogenicity, and thus in this respect, the antithrombogenic ability of the neo-intima may be attenuated after long duration. Less