[Research on the relationship between expression of VEGF and high altitude pulmonary edema]

Abstract

Objective: To investigate the relationship between the expression of VEGF and the incidence of high altitude pulmonary edema (HAPE) and the mechanism of high altitude acclimatization-adaptation.

Methods: Pulmonary artery endothelial cells (PAEC) of rat were cultured. The expression of VEGF in PAEC was detected using RT-PCR and ELISA. Rats were divided randomly into five groups by weight: control, acute hypoxia (exposed to a simulated 8,000 m altitude for 4 hours), and three intermittent hypoxia groups (exposed to a simulated 3,000 m or 5,000 m altitude for 2 weeks, 4 hours a day, then to a simulated 8,000 m altitude for 4 hours). VEGF in the lung was detected using immunohis to chemistry and slot hybridization, and the changes of pathology in the lung were observed. VEGF in the blood plasma of rats, in men who immigrated to high altitude at different times, and in those who suffered from high altitude pulmonary edema were measured using ELISA.

Results: The expression of VEGF in PAEC was increased under hypoxia condition (1% O2) (P < 0.01). In the blood plasma and lung of rats during hypoxia, levels of VEGF and VEGF mRNA were higher than that in the control group. VEGF in acute hypoxia group was increased significantly compared with that in the intermittent hypoxia groups. Leakage of fluid in the lung of rats was observed in the acute hypoxia group. The longer the rats acclimatized, the lower the level of VEGF expressed, and the less the fluid leaked in the lung. The same tendency could be seen in humans. The level of VEGF in patients with high altitude pulmonary edema pre-therapy was higher than that measured post-therapy.

Conclusions: Hypoxia could stimulate the expression of VEGF, and the upregulated expression of VEGF is one of the most important factors of incidence of high altitude pulmonary edema.