Humoral Control of Erythropoietic Activity in Man During and After Altitude Exposure.

Abstract

Summary The erythropoietic stimulating factor was studied in natives and newcomers to high altitude (14,900 feet). An increase was found only in the group of newcomers after 24 hours of exposure. The possibility of the existence of an erythropoietic depressing factor is suggested from the investigation of a group of high altitude polycythemic subjects brought down to sea level, where they were followed 72 hours, 10 days and 20 days after arrival. Plasma obtained from them at these time periods when injected into rats had a depressing erythropoietic action.