Expression of Urotensin II in pneumoangiogram of hypoxic rats

Objective To observe the expression of Ureotensin Ⅱ (U Ⅱ) in hypoxic hypertension rats pneumoangiogram,and its role in hypoxic hypertension.Methods Twenty male Sprague-Drawley rats were randomly allocated into two groups:control group and hypoxic group.The animal model of hypoxic pulmonary hypertension was established by exposing the rats to normobaric hypoxic condition for three weeks.The mean pulmonary pressure(mPAP) was measured by inserting catheter.The right ventricle (RV) and left ventricle plus septum (LV+S) of rat were weighed respectively and the RV/(LV+S) was calculated.The index of wall thickness of rat pulmonary arteriole (WT％)-percentage of the wall thickness in the external diameter and (WA％)-percentage of the wall area in the total vascular area were measured by a computerized image analyzer.The expressing level of BMP4 mRNA in pulmonary artererioles were measured by in-situ hybridization.Results ① In control group the mPAP and RV/(LV +S)were (17.2 ± 2.93) mm Hg and (22.13 ± 0.95) ％,in hypoxic group,however,they increased to (29.3±2.27) mm Hg and (33.18±1.58)％(P ＜0.01 respectively).② In control group the index of wall thickness of rat pulmonary arteriole were [WT％:(12.21 ± 0.78) ％,WA％:(44.79 ± 2.16) ％],while in hypoxic group they were [WT％:(25.14 ± 1.85) ％,WA％:(74.77 ± 4.52) ％] (P ＜ 0.01),which raised obviously compared with the control group (P ＜ 0.01).③ The positive degree of U Ⅱ mRNA and U Ⅱ in hypoxic group were (0.33 ± 0.05) and (0.48 ± 0.09) respectively,increased significantly compared with the control group (P ＜ 0.01).Conclusions The expression of U Ⅱ in hypoxic rats pneumoangiogram increased obviously,and U Ⅱ may be important in the hypoxic pulmonary hypertension. Key words: Hypoxia hypertension;  Pulmonary;  Urotensin Ⅱ