Effect Of Intermittent Hypoxia Training On Erythropoiesis And The Antioxidant Ability In Red Blood Cell

Training at moderate altitude is often used by athletes from a variety of sports to improve their aerobic capacity. In order to avoid the detrimental effects of reduced training intensity at hypoxic condition, many simulated altitude training have been supposed. Intermittent normobaric hypoxia training is one style of simulated altitude training too.The study was to investigate that effects of 4 weeks intermittent hypoxia training(IHT) on erythropoiesis and the antioxidant ability in erythrocytes. Some markers in realation to erythorpoiesis and antioxidant system were measured and analyzed. We undertook these data in order to test the hypothesis that IHT is helpful to exercise performance and maximal oxygen uptake (Vo2max).Our research subjects are 15 male students who were randomly divided into groups of control and of IHT. Two groups took part in same daily study and exercise during the experiment. The INT group inhaled a intermittent hypoxia gas mixture (O2% is 14%, 12% , 10%) 50-60 minutes daily for 4 weeks (6d/week). Blood of two groups were collected 2ml for measuring red cell count, hematocrit (Hct), hemoglobin (Hb), reticulocytes hematocrit (HctRet), erythropoietin (EPO) and soluable serum transferrin receptor (sTfr) before IHT, on days 1, 3, 10, 15, 17, 22, 24 during IHT and on days 5, 8,14 of post-IHT. Both groups completed incremental exercise to exhaustion on the treadmill before and after IHT. The MDA and human red cell protect protein (HRPRP) concentration, SOD and GSH-PX activity and blood lactic acid were measured at rest and post-exercise respectively. The Voimax , heard rate (HR) and the time to exhaustion were measured as well.The results are follow:1. In our study, IHT could stimulate erythropoietin secretion that lead to erythpopoietic response. We observed that serum EPO significantly increased after one day hypoxia. After the initial peak, serum EPO decreased if the concentration of oxygen was not decreased continually. The measurement of sTfr was used as indicator of erythropoietic activity as EPO. In our study, the sTfr show a significantly increased after EPO has been increased for one week and still remained high level after IHT. It reflect an activity of erythropoiesis increase both duing IHT and post-IHT.2. In our study, the red cell count and Hct were significantly elevated since IHT. It indicate that intermittent exposure to hypoxia 50-60 minutes daily for 4 weeks induce a similar stimulation of erythropoiesis as high- altitude-training. The Hb values did not show any significant changes during our experiment. We suggest that the blood volume and total hemoglobin mass should be measured and nutrition supply should be monitored and controled in later research of IHT.3. The MDA concentration and activity of GSH-PX in erythrocytes were significantly increased after incremental exercise to exhaustion. At the same time, activity of SOD and the concentration of HRPRP in erythrocytes did not change significantly. It indicate that the possibility of oxidative damage in erythrocytes was caused by reactive oxygen species (ROS) increasing post-exercise. The different showing of GSH-PX, SOD activities and HRPRP may be relate to the type of exercise what we took.4. In our study, antioxidant capacity showed a statistically increasing post-hypoxia compared with pre-hypoxia. The activities of SOD, GSH-PX and concentration of HRPRP were increased both at rest and post-exercise compared with what they were 4 weeks before. It show that hypoxia increased ROS which caused elevating of activity of antioxidant enzymes and concentration of HRPRP. It suggested that INT could increase antioxidant capacity and be helpful to improve arobic capacity.5. This study show that Vo2max increased and the time to exhaustion decreased significantly after 4 weeks of IHT. It indicated that sports performance can be enhanced effectively by IHT. It suggested that IHT may be used in the sport training.