摘要
目的 研究钾通道开放剂Cromakalim对大鼠慢性低氧性肺动脉高压的阻抑效应。方法 3 0只大鼠随机分为 3组 ,每组 10只。Ⅰ组为正常对照组 ,Ⅱ组为低氧组 ,缺氧 [吸入氧浓度 ( 10± 0 .5 ) % ] 3周 ,Ⅲ组为阻抑组 ,同样缺氧 3周 ,分别于缺氧前后按 3 0 0 μg/kg剂量给大鼠腹腔注射钾通道开放剂Cromakalim。 3周后 ,行右心插管分别测定 3组大鼠的肺动脉压和肺血管阻力 ;然后剖胸取出大鼠肺脏行HE染色 ,经光镜观察和图像分析肺小动脉。结果 Ⅱ组大鼠于缺氧后 ,肺动脉压和肺血管阻力比Ⅰ组明显增高 ,肺小动脉管壁增厚、狭窄。其管壁厚度占血管外径的百分比 (WT % )和管壁面积占血管总面积的百分比 (WA % )与Ⅰ组相比明显增加。Ⅲ组大鼠的肺动脉压和肺血管阻力增高不明显 ,其WT %和WA %亦无明显增大 ,与正常对照组相比 ,二者无明显差异 ;但与Ⅱ组相比 ,二者有明显差异。结论 肺动脉高压发展中肺小动脉平滑肌细胞结构与功能的变化可能与钾通道活性改变相关 。
Objective To investigate the preventive effect of potassium opener on the development chronic hypoxic hypertension in rats.Methods 30 male Wistar rats were divided into 3 groups at random,10 rats in each group.Group Ⅰ served as control,group Ⅱ were exposed to hypoxia(FiO 2=0.10±0.005)for 3 weeks,group Ⅲ were administered to cromakalim(300μg/kg·day) before and after they were placed in hypoxic conditions for the same time just like group Ⅱ.The mean pulmonary artery pressure(mPAP),vascular resistence(PVR)and cardiac output(CO) were determined by right cardiac catheterization,then histological sections of lungs were examined using a computerized image analysis system.Results The mPAP and PVR in group Ⅱ was much higher than those in group Ⅰ(P<0.01),whereas those values in group Ⅲhad no difference compared with group Ⅰ(P>0.05) and appeared much lower than those in group Ⅱ(P<0.01).The chronic hypoxia elicited the thickness of wall and the narrowing of the lumen of pulmonary arterioles.The ratio of vascular wall thickness/vascular external diameter(WT%) and the ratio of vascular wall area/total vascular area(WA%) were increased in group Ⅱ(P<0.01) compared with groupⅠ.The values of WT% and WA% in group Ⅲ were lower than those in group Ⅱ(P<0.01～0.05)and had no difference compared with group Ⅰ(P>05).Conclusion The Structural and functional alterations in pulmonary arterial myocytes during the development of chronic hypoxic pulmonary hypertension are related with the change in potassium channel activity.Administration of potassium channel openers can prevent the development of chronic hypoxic pulmonary hypertension
出处
《四川医学》
CAS
2004年第12期1277-1279,共3页
Sichuan Medical Journal
基金
四川省青年基金 (S0 3 - 1 )
成都军区总医院资助课题 (编号 0 2Y0 0 6)
关键词
慢性低氧
肺动脉高压
形态学
钾通道开放剂
chronic hypoxia
pulmonary hypertension
imagae analysis system
potassium channel opener
