Expression of Hif-1α in the Lungs of Rats with Pulmonary Hypertension Induced by Monocrotaline

To observe the expression of hypoxia-inducible factor 1 alpha(H1F-1α) in rat pulmonary in different phases of pulmonary hypertention and to explore the role of HIF-la in the pathogenesis of monocrotaline(MCT group) -induced pulmonary hypertension. Methods: Forty-eight rats were randomly assigned into the control group and monocrotaline-treated group. Monocrataline was delivered as a single subcutaneous injection (60 mg/kg) into male Sprague-Dawley rats weighting about 180 g. The mean pulmonary arterial pressure (mPAP) was measured by right-heart catheterization. Heart weight was measured and a weight ratio of right ventricle ( RV ) to left ventricle plus septum (LV + SP) was calculated. Western blot and Reverse transcription-polymerase chain reaction ( RT-PCR) were used to examine the levels of protein and mRNA of HIF-1α in lungs at different time after MCT group the injection. Results: On the 14th day after MCT group injection, the right ventricular hypertrophy was found, and mPAP increased on the 21 th day after MCT injection. RT-PCR revealed the enhanced expression of HIF-la mRNA in lung tissue on the 21th day after administration of MCT(P 0. 01) . Western blot analysis demonstrated the increased HIF-la synthetic capacity in lungs of MCT group-treated rats as compared to that of the controls. Conclusion: HIF-1α expression was elevated in the lung of pulmonary hypertensive rats induced by MCT group. HIF-1α might be involved in the pathogenesis of pulmonary hypertension and play an important role in the development of MCT group-induced pulmonary hypertension.