肝前型门静脉高压症大鼠血浆PGI2水平变化及其机理的实验研究

检测肝前型门静脉高压症（ＰＶＬ）大鼠不同时期血流动力学变化、血浆前列环素（ＰＧＩ２）水平和计算内脏ＰＧＩ２合成量，结果ＰＶＬ第五天以后全身和内脏出现高动力循环状态；ＰＶＬ术后内脏ＰＧＩ２合成量和门静脉ＰＧＩ２水平持续升高，后者与门静脉压力呈显著相关（ｒ＝０．８０，Ｐ＜０．００１），第五天以后，由于大量门体分流形成，主动脉ＰＧＩ２也明显升高，且与门静脉ＰＧＩ２水平呈显著相关（ｒ＝０．９７，ｐ＜０．００１；ｒ＝０．９０，Ｐ＜０．００１）。表明ＰＶＬ大鼠血浆ＰＧＩ２水平升高可能是内脏过多合成的ＰＧＩ２逃避了肝脏的灭活作用所致，且对高动力循环状态形成起介导作用。

Experimental Studies on the Change of Plasma PGI_2 Level and Its Mechanism in Rats with Prehepatic Portal Hypertension

Hemodynamic changes and plasma prostacyclin (PGI2)levels were measured and splanchnic PGI2 production was calculated chionologically in rats with prehepatic portal hypertension(PVL) .The results showed that from 5th day on the systemic and splanchnic hyperdynamic circulatory states occured in PVL rats;Splanchnic PGI2 production and portal PGI2 levels rose immediately after PVL and remained elevated thhereafter,and portal PGI2 levels correlated highly with portal pressure(r= 0.80, P<0.001). From 5th day on aortic artery PGI2 levels also rose because of the development of high-grade portosystemic shunt,and correlated highly with portal PGI2 leveIs(r=0.97 , P<0.001 ;r = 0.90,P<0.001).These results suggest that the elevated plasma PGI2 produc tion which avoids hepatic degradation to mediate the hyperdynamic circulatory state.