Erythropoietin does not reduce plasma lactate, H+, and K+ during intense exercise

Abstract

It is investigated if recombinant human erythropoietin (rHuEPO) treatment for 15 weeks (n=8) reduces extracellular accumulation of metabolic stress markers such as lactate, H+, and K+ during incremental exhaustive exercise. After rHuEPO treatment, normalization of blood volume and composition by hemodilution preceded an additional incremental test. Group averages were calculated for an exercise intensity approximate to 80% of pre-rHuEPO peak power output. After rHuEPO treatment, leg lactate release to the plasma compartment was similar to before (4.3 +/- 1.6 vs 3.9 +/- 2.5mmol/min) and remained similar after hemodilution. Venous lactate concentration was higher (P<0.05) after rHuEPO treatment (7.1 +/- 1.6 vs 5.2 +/- 2.1mM). Leg H+ release to the plasma compartment after rHuEPO was similar to before (19.6 +/- 5.4 vs 17.6 +/- 6.0mmol/min) and remained similar after hemodilution. Nevertheless, venous pH was lower (P<0.05) after rHuEPO treatment (7.18 +/- 0.04 vs 7.22 +/- 0.05). Leg K+ release to the plasma compartment after rHuEPO treatment was similar to before (0.8 +/- 0.5 vs 0.7 +/- 0.7mmol/min) and remained similar after hemodilution. Additionally, venous K+ concentrations were similar after vs before rHuEPO (5.3 +/- 0.3 vs 5.1 +/- 0.4mM). In conclusion, rHuEPO does not reduce plasma accumulation of lactate, H+, and K+ at work rates corresponding to approximate to 80% of peak power output.