Effect of Panax notoginoside on pulmonary arterial pressure and expression of p38 MAPK in lung tissues of hypoxic rats

AIM: To observe the effect of Panax notoginoside (PNS) on the pulmonary artery pressure and the p38 mitogen-activated protein kinase(p38 MAPK) in lung tissues of rats treated with hypoxia. METHODS: Thirty adult male SD rats were randomly divided into 3 groups. The rats in normal control group were exposed to normal conditions, the rats in hypoxia group were exposed to isobaric hypoxia, and the rats in hypoxia+PNS group were treated with PNS under the condition of hypoxia. After 4 weeks of treatment, the mean pulmonary arterial pressure (mPAP) and the mean carotid arterial pressure (mCAP) were measured by cardiac catheterization. The heart was isolated, and the right ventricle (RV), left ventricle plus ventricular septum (LV+S) were weighed to calculate the ratio of RV/(LV+S).The quantity of phospho-p38 MAPK(p-p38 MAPK) in rat pulmonary arterioles was determined by the method of immunohistochemistry and the mRNA content of p38 MAPK was tested by RT-PCR. RESULTS: The mPAP and RV/(LV+S) in hypoxia group were higher than those in normal control group. The expression of p-p38 MAPK in rat pulmonary arterioles and p38 MAPK mRNA in the lung tissues were higher than those in normal control group (P<0.05). The mPAP, RV/(LV+S), the expression of p-p38 MAPK in rat pulmonary arterioles and p38 MAPK mRNA in the lung tissues in hypoxia+PNS group were significantly lower than those in hypoxia group (P<0.05).CONCLUSION: PNS possesses the preventive and therapeutic effect on hypoxic pulmonary hypertension by decreasing p-p38 MAPK and down-regulation of p38 MAPK mRNA in the lungs.