[Serum levels and significance of HIF-1α and HIF-2α in healthy Tibetan and Han residents at different altitudes].

Objective To explore the serum levels and significance of hypoxic inducible factor (HIF)-1α and HIF-2α in Tibetan and Han residents living at different altitudes. Methods A total of 100 healthy adults of Han in plain (altitude 5 m, group P) and Tibetan and Han at moderate altitude (2260 m, groups M1& M2) and high altitude (4380 m, groups H1& H2)(n=20 each) were selected from June 2010 to August 2010.Venous blood samples were collected in the morning.The serum concentrations of HIF-1α and HIF-2α were measured with enzyme-linked immunosorbent assay (ELISA) to analyze the correlations of HIF-1αand HIF-2α with arterial partial pressure of oxygen (PaO2) and hemoglobin (Hb). Results The level of HIF-1α in group H2 ((6.06±1.85) μg/L) was higher than that in groups P ((4.56±0.85) μg/L, P 0.05).No correlation existed between HIF-1α and Hb in Tibetan.A positive correlation existed between HIF-2αand Hb in Tibetan (r=0.325, P<0.01). Conclusions The changes of HIF-1αand HIF-2αvary for Tibetan and Han residents at different altitudes.And the level of HIF-2αis consistent with the change of Hb.As compared with HIF-1α, HIF-2α may play a more important role in regulating Hb. Key words: Altitude; Hypoxic-induciblefactor1; Tibetan; Han