Journal of Applied Physiology, Vol 64, Issue 4 1644-1649, Copyright © 1988 by American Physiological Society
Effect of simulated altitude erythrocythemia in women on hemoglobin flow rate during exercise
R. J. Robertson, R. Gilcher, K. F. Metz, C. J. Caspersen, T. G. Allison, R. A. Abbott, G. S. Skrinar, J. R. Krause and P. A. Nixon
Human Energy Research Laboratory, School of Medicine, University of Pittsburgh, Pennsylvania 15261.
The effect of simulated altitude erythrocythemia on hemoglobin flow rate
and maximal O2 uptake (VO2max) was determined for nine women sea-level
residents. Test conditions included normoxia and normobaric hypoxia (16%
O2-84% N2). Cycle tests were performed under normoxia (T1-N) and hypoxia
(T1-H) at prereinfusion control and under hypoxia 48 h after a placebo
infusion (T2-H) and 48 h after autologous infusion of 334 ml of
erythrocytes (T3-H). Hematocrit (38.1-44.9%) and hemoglobin concentration
(12.7-14.7 g.dl-1) increased from control to postreinfusion. At peak
exercise, VO2max decreased from T1-N (2.40 l.min-1) to T1-H (2.15 l.min-1)
then increased at T3-H (2.37 l.min-1). Maximal arterial-mixed venous O2
difference decreased from T1-N to T1-H and increased at T3-H. Cardiac
output (Q), stroke volume, heart rate, and total peripheral resistance
during maximal exercise were unchanged from T1-N through T3-H. Hemoglobin
flow rate (Hb flow) at maximum did not change from T1-N to T1-H but
increased at T3-H. When compared with submaximal values for T1-N, VO2 was
unchanged at T1-H and T3-H; Q increased at T1-H and decreased at T3-H;
arterial-mixed venous O2 difference decreased at T1-H and increased at
T3-H; Hb flow did not change at T1-N but increased at T3-H. For young
women, simulated altitude erythrocythemia increased peak Hb flow and
decreased physiological altitude (227.8 m) but did not affect maximum
cardiac output (Qmax).
