Objective: To investigate the interventive effects of Salvia przewalskii Maxim.(SPM)on high-altitude pulmonary hypertension(HAPH)in rats and possible mechanism.
Methods: The male SD rats were randomly divided into the control group, the hypoxia group and SPM(0.5 g/kg,1 g/kg and 2 g/kg) group. There were 14 rats in each group. The rats in control group were feed in Xining(with an altitude about 2 260 m), and the other group rats were all feed in Maduo county people's hospital(with an altitude about 4 260 m). The rats in SPM groups were treated with SPM at the doses of 0.5 g/kg,1 g/kg and 2 g/kg by gavage respectively (100 g/ml). The rats in control and the hypoxia groups were received equal volume of distilled water, once a day. After 4 weeks, the mean pulmonary artery pressure (mPAP) of rats was measured and the same part of lung tissue of each rat was collected and stored in liquid nitrogen. Then the relative mRNA expression levels of the proliferation cell nuclear antigen(PCNA), the cell cycle dependent kinase 4(CDK4), CyclinD1, RhoA, ROCK1, ROCK2 in lung tissues of each group rats were all tested by RT-PCR.
Results: Compared with the control group, the mPAP and the relative mRNA expression levels of PCNA, CDK4, CyclinD1, RhoA, ROCK1 and ROCK2 were increased significantly in the hypoxia group(P＜0.01). Compared with the hypoxia group, the mPAP and the relative mRNA expression levels of PCNA, CDK4, CyclinD1, RhoA, ROCK1 and ROCK2 in the lung tissues of the SPM group rats were all decreased significantly(P＜ 0.05 or P＜0.01).
Conclusion: SPM can prevent the HAPH in rats, and the mechanisms may be related to the inhibition of the excessive proliferation of smooth muscle cells in pulmonary artery and the excessive activation of the RhoA/Rho kinase(ROCK) signaling pathway.