大鼠肝硬化形成过程中胃黏膜微循环内皮素A受体mRNA的表达及其意义

目的观察大鼠肝硬化门静脉高压形成过程中内皮素A受体mRNA在胃黏膜微循环血管上的表达 ,探讨内皮素及其受体对肝硬化门静脉高压大鼠胃黏膜微循环的调节机制。方法应用mRNA原位杂交确定内皮素A受体的部位 ,并进行半定量分析。结果大鼠肝硬化门静脉高压形成过程中门静脉及外周血浆内皮素水平随门静脉压力升高而降低。胃黏膜内皮素A受体mR NA主要在黏膜基底部的微循环前微动脉和后微静脉血管壁表达 ,其中动脉表达明显强于静脉。其表达与门静脉压力呈正相关 (r =0 86 9,P <0 0 5 ) ,与门静脉及外周血内皮素水平呈负相关 (r =-0 797、- 0 74 1,P <0 0 5 )。结论大鼠肝硬化门静脉高压形成过程中外周及门静脉血浆内皮素水平进行性降低 ;胃黏膜微循环内皮素A受体mRNA表达量增加 ,呈现上调趋势 ;内皮素及其受体mR NA表达变化可能与胃黏膜微循环功能障碍有关。

Endothelin A receptor mRNA expression in microvessels of gastric mucosa during the development of liver cirrhosis in rats

Objective To observe endothelin A receptor mRNA expression in gastric mucosal microvessels and to explore the mechanism by which endothelin was enrolled in the development of liver cirrhosis and portal hypertension. Methods In situ hybridization of mRNA was used to detect the location and the expression level of endothelin A receptor in gastric mucosa microvessels in Wistar rats. Results Along with the formation of liver cirrhosis and portal hypertension, peripheral and portal blood endothelin level was decreased, ETA mRNA was expressed mainly in the postcapillary venule and precapillary arteriole and enhanced remarkably with the reduction of endothelin level and elevation of portal pressure and that was dramaticlly increased in the arteriole wall. The expression was correlated positively with portal pressure(r=0.869, P<0.05 ),negatively with level of endothelin in portal and peripheral circulation(r=-0.797; -0.741 ,P<0.05). Conclusions Endothelin level in portal and peripheral blood decreased gradually with the formation of liver cirrhosis and portal hypertension in rats; ETA mRNA expression increased in gastric mucosal microcirculation and up-regulated with the descending of endothelin level; These changes may cause dysfunction of gastric mucosal microcirculation in cirrhotic and portal hypertensive rats.