Effects of erythrocyte infusion on o2 max at high altitude.
Young, Andrew J., Michael N. Sawka, Stephen R. Muza, Robert Boushel,
Timothy Lyons, Paul B. Rock, Beau J. Freund, Ray Waters, Allen
Cymerman, Kent B. Pandolf, and C. Robert Valeri.
US Army Research Institute of Environmental Medicine, Natick, MA
01760-5007; and Naval Blood Research Laboratory, Boston University
Medical Center, Boston, MA 02118
APStracts 3:0105A, 1996.
This study investigated whether autologous erythrocyte infusion would
ameliorate the decrement in maximal oxygen uptake (O2MAX) experienced
by lowlanders when they ascend to high altitude. Sixteen men's O2MAX
was measured (treadmill running) at sea level (SL), and on the first
(HA1) and ninth (HA9) day of high altitude (4300 m) residence. After
O2MAX was measured at SL, subjects were divided into two matched
groups (N = 8). Twenty-four hrs before ascent to high altitude, the
experimental group received a 700 ml infusion of autologous
erythrocytes and saline (42% hematocrit), while the control group
received only saline. The O2MAX ( + se) of erythrocyte-infused (54 +
1 ml x kg-1 x min-1) and control subjects (52 + 2 ml x kg-1 x min-1)
did not differ at SL before infusion. The decrement in O2MAX on HA1
did not differ between groups, averaging 26% overall, despite higher
(P < 0.01) arterial hematocrit, hemoglobin concentration and
arterial oxygen content (CaO2) in the erythrocyte-infused subjects.
By HA9, there were no longer any differences in hematocrit,
hemoglobin concentration, or CaO2 between groups. No change in O2MAX
occurred between HA1 and HA9 for either group. Thus, despite
increasing arterial oxygen carrying capacity, autologous erythrocyte
infusion did not ameliorate the decrement in O2max at 4300 m
altitude.
Received 9 July 1995; accepted in final form 31 January 1996.
APS Manuscript Number A710-5.
Article publication pending Journal of Applied Physiology.
ISSN 1080-4757 Copyright 1996 The American Physiological Society.
Published in APStracts on 13 March 96