Effect of simulated altitude erythrocythemia in women on hemoglobin flow rate during exercise

Human Energy Research Laboratory, School of Medicine, University of Pittsburgh, Pennsylvania 15261.
Journal of Applied Physiology (Impact Factor: 3.06). 05/1988; 64(4):1644-9.
Source: PubMed


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).

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    • "To our knowledge, only one research group has previously evaluated the effect of an acute rise in CaO2 and red blood cell volume on V̇O2max during moderate acute hypoxia. Their studies showed that after autologous blood re-infusion V̇O2max was increased by 9.3% at 2278 m [26] and by 13% at 3566 m [27]. It has also recently been reported that at moderate altitude of 2340 m, the 15% increase in hemoglobin concentration induced by three weeks of acclimatization in athletes resulted in a progressive rise in CaO2 that was associated with a 8.9% increase in V̇O2max from acute to chronic exposure to 2340 m [28]. "
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