Effects of exercise on plasma erythropoietin in natives living permanently at high altitude

Abstract

Abstract. The effects of inspiratory hypoxia on the erythropoietin (EPO) system decisively depend on the duration of the exposure to the hypoxic environment. Whereas a stay of some hours in a hypobaric chamber leads to markedly increased serum [EPO] (Eckardt et al. 1989), it could be demonstrated by Milledge and Cotes (1985) that members of a Himalaya expedition had, after a rapid increase in EPO values, presented decreasing EPO values during the second half of their altitude exposure. Furthermore, Winslow et al. (1989) showed low EPO concentrations in the blood of high-altitude natives from Nepal and Chile, which are similar to those of subjects living at sea level. The reasons for the adaptation of the EPO response to chronic hypoxia are not completely understood. It may only in part be attributed to other adaptive processes, e.g., increased hemoglobin concentration [Hb] or lower pH values.