The Effect of Chronic Erythrocytic Polycythemia and High Altitude upon Plasma and Blood Volumes 1

Conclusion

Chronic erythrocytic polycythemias were produced in adult female domestic fowl (chicken): (a) hormonally (by androgen injection) at sea level, or (b) by protracted high-altitude (12,500 ft) exposure. Plasma volumes were determined directly by injected ¹³¹I human serum albumin dilution methods. Total body erythrocyte and blood volumes were calculated from plasma volumes and adjusted peripheral hematocrits. Androgen treatment or high-altitude exposure similarly increased the hematocrits approximately 45% and the body erythrocytic volumes approximately 65%. These two procedures, however, affected the plasma volumes differently. No change in plasma volume was found at high altitude; however, there was a significant (17%) reduction in plasma volume in the androgen-treated birds as compared with either the sea-level controls or the high-altitude birds. It appears, therefore, that the vascular system of the body accounts for an increase in erythrocytic mass by either (a) a reduction in plasma volume or (b) no change in plasma volume, in which case differential changes occur in total blood volumes.