Membrane lipid diffusion and band 3 protein changes in human erythrocytes due to acute hypobaric hypoxia

Because it has been reported that hypoxia in rats may promote lipid peroxid ation and other free radical reactions that could modify membrane lipids an d proteins, the effect of acute hypobaric hypoxia on human erythrocyte memb ranes was investigated. 12-(1-Pyrene)dodecanoic acid fluorescent probe was used to assess short-range lateral diffusion status in the membrane bilayer . Membrane protein modification was detected by SDS-PAGE. Healthy young men were exposed for 20 min to the hypobaric hypoxia, simulating an altitude o f 4,500 m. Under this condition, erythrocyte membrane Lipids reached a stat e of higher lateral diffusivity with respect to normobaric conditions and m embrane band 3 protein was modified, becoming more susceptible to membrane- bound proteinases. These observations suggest that acute hypobaric hypoxia may promote an oxidative stress condition in the erythrocyte membrane.