肺动脉高压模型大鼠循环内皮祖细胞与血浆一氧化氮水平相关性的实验研究

目的 探讨肺动脉高压(PH)模型大鼠循环内皮祖细胞(EPC)水平的变化及其与血浆一氧化氮(NO)浓度的关系.方法 利用野百合碱诱导大鼠发生肺动脉高压,使用流式细胞仪对其外周血CD45 阴性、CD34/Flk-1 双阳性的单个核细胞计数,以表示循环EPC,采用Greiss 法对其血浆NO 浓度进行检测.利用简单线性回归分析二者之间的关系.同时,对体外培养条件下循环EPC 的产量,CD34、Flk-1 的表达情况进行检测.结果 PH 模型组循环EPC 水平明显低于对照组[(0.016 ±0.007)% vs.(0.031 ±0.011)%,t ＝3.144,P ＜0.01].血浆NO 浓度亦显著下降[(19.66 ±2.78)μmol/L vs.(54.31 ±3.81)μmol/L,t ＝20.784,P ＜0.01].二者之间呈正相关(r ＝0.792,P ＜0.05).在体外培养条件下,PH 模型组EPC 的数量以及CD34、Flk-1 的表达亦较对照组明显下调.结论 PH 的发生可能与血浆NO 浓度降低导致循环EPC 水平下调有关.

The experimental study of correlation between the circulating endothelial progenitor cells and serum nitric oxide in rat model of pulmonary hypertension

Objective The present study was designed to investigate the change of circulating endothelial progenitor cells（EPC） and its relationship with the change of serum nitric oxide（NO） in rat model of pulmonary hypertension（PH）.Methods The rat was injected with crotaline to induce model of PH,the number of peripheral circulating EPC was detected by flow cytometry,which is characterized by negative of CD45,double positive of CD34/FLK-1.The serum concentration of NO was assessed by Greiss method.The relationship of them was analyzed by simple linear regression.Meanwhile,the output of EPC,the expression of CD34 and Flk-1 were assessed when peripheral mononuclear cells cultured in vitro.Results The number of peripheral circulating EPC in PH group was lower than it in control group[（0.016±0.007）% vs.（0.031±0.011）%,t=3.144,P〈0.01].The serum concentration of NO in PH group was lower than it in control group too [（19.66±2.78）μmol/L vs.（54.31±3.81）μmol/L,t=20.784,P〈0.01].In PH group the number of circulating EPC was positively correlated with the level of nitricoxide（r=0.792,P〈0.05）.Furthermore the number of EPC and the expression of CD34 and Flk-1 were down-regulated in PH model group than in control group when cultured in vitro.Conclusions The occurrence of PH may be associated with the down-regulation of circulating EPC,which induced by the decrease of serum concentration of NO.