RESUMO
AIM: To investigate the effects of intermittent hypoxic exposure and normoxic convalescence on the parameter of erythrocyte and serum hypoxia inducible factor1 alpha (HIF-1α) and erythropoietin (EPO)levels. METHODS: Rat models of intermittent hypoxic exposure were established, combined with the clinical research on volunteers experiencing the intermittent plateau work. Blood samples for red blood cell (RBC) counts, hemoglobin (Hb) and hematocrit (HCT) were collected, serum HIF-1α and EPO levels were measured using enzymelinked immunosorbentassy. RESULTS: RBC counts, Hb concentration and HCT were significantly higher than the normoxic group (P < 0.05), after exposure of rats to hypoxia from 7 to 28 days. Compared with the normoxic group, serum HIF-1α levels were higher in the group of IH3, 7, 14 days, and EPO had a corresponding increase in the group of IH3, 7 days. Then, a decrease was observed in parameter of erythrocyte and serum HIF-1α and EPO levels after 14 days normoxic convalescence treat. In volunteers studies, RBC counts in 8 monthes group and Hb concentration in 2 years group were significantly higher than the plain group (P < 0.05). The change of HCT was nearly the same as RBC, and HCT in 2 years group was higher than the plain group (P < 0.05). Compared with the plain group, EPO had no significant differences in any of plateau group. CONCLUSION: Intermittent hypoxic exposure can enhance serum hypoxia inducible factor-1 alpha and erythropoietin levels and the generation of red blood cells, which leads to an increase in hemoglobincon concentration and hematocrit. The results have changed with the hypoxic exposure period prolonged. Normoxic convalescence after intermittent hypoxic exposure can make the related indexes reduced, and contribute to the organism recovery.