Effects of Rhodiola tibetica on lung tissue of rats with high altitude pulmonary edema

Objective To observe the effects of Rhodiola tibetica(R.tibetica)on lung tissue of rats with high altitude pulmonary edema and the expression of hypoxia-inducible factor-1a(HIF-1a)in the rats. Methods Totally 50 male SD rats were randomly divided into 5 groups:control group,normal saline treatment group,R.tibetica acclimatization group at low altitude(in Xi'an area with the altitude of 5 meters),hypoxia group,and R.tibetica acclimatization group at high altitude(in Naqu area with the altitude of 4500 meters).The changes of lung tissue of the rats were observed with light and electron microscope.HIF-1 expression in lung tissue was detected with immunohistochemical method and HIF-1a mRNA in lung tissue was determined with reverse transcriplase-PCR(RT-PCR). Results Observations of microstructure and ultrastructure of lung tissues revealed obvious high altitude edema in hypoxia groups and the mitigated edema in R.tibetica acclimatization group was observed.The expression of HIF-1a mRNA of R.tibetica acclimatization group at high altitude was significantly higher than that of control group and hypoxia group(0.463±0.069 vs 0.231±0.037 and 0.219±0.047,P<0.001). Conclusion R.tibetica can increase the expression of HIF-1a mRNA in lung tissue and mitigate high altitude pulmonary edema in hypoxic rats.