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

1.大鼠离体心：用NO微电极(100um；1Pa.apprxeq.[)1.5 nM NO]测定大鼠离体心(以Langendorff模式灌流)冠脉灌流液中NO浓度。冠脉灌流液中NO浓度随着灌流压力的增加而增加(47()sy.+-。[)6Pa40 cm H&lt；@d22@&gt；d2O，69()sy.+-。[)10Pa70 cmh&lt；@d22@&gt；d2O，99()sy.+-。[)17帕，100 cmh；lt；@d22@&gt；d2O)。缺血1min，再灌流时出现一过性NO浓度高峰，10min后出现一过性小峰，随后逐渐升高(达到稳定期)(22()sy.+-)。[]3Pa1分钟vs 124(正负)。[)17帕，10分钟)。这些结果似乎反映了缺血过程中累积的NO被冲刷掉，以及再灌流过程中切应力的增加。人造血管：两种人造血管(Terumo的PF-V和Gore的ePTFE，长度均为10厘米)为…更多的是通过连接到股动脉植入狗体内。在一段时间后，分离每条血管，测量内皮细胞没有产生任何物质。1 mM L-精氨酸和100um L-钠灌流测得的NO电流的差异为：2周后(PF-V：52pA，49pA)，1个月后(PF-V：45pA，ePTFE：233pA)，12个月后(无显著变化)，13个月后(无显著变化)。这些结果表明，在每条血管的管腔侧形成的新生内膜在短时间内具有产生NO的能力，但在长时间(约1年)后，内皮细胞认识到不再产生NO的生理功能，从而可能导致NO合成酶活性和/或NO合成酶数量的下降。内皮细胞产生的NO与抗血栓形成能力直接相关，因此，在这方面，新血管内膜的抗血栓形成能力可能在长时间后减弱。较少

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