Affiliations: UPRES EA 3596 (ACTES), Université des Antilles et de la Guyane, Campus de Fouillole, 97159 Pointe-à-Pitre, Guadeloupe | UPRES EA 3759 (Approche bio-psycho-sociale du dopage), Université Montpellier 1, 700 Avenue du Pic Saint Loup, 34090 Montpellier, France | UPRES EA 701 (Physiologie des Interactions), Hopital Arnaud de Villeneuve, Service EFR, 34295 Montpellier cedex 5, France
Note: [] Corresponding author: Philippe Connes, PhD, Laboratoire ACTES (EA 3596), Université des Antilles et de la Guyane, Campus de Fouillole, 97159 Pointe-à-Pitre, Guadeloupe (French West Indies). E-mail: [email protected].
Abstract: Exercise and lactate usually change blood rheology, particularly red blood cell (RBC) deformability. The effect of lactate on RBC aggregation is unknown. The present study tested the in vivo effects of exercise on both lactate and RBC aggregation and the in vitro effects of lactate on RBC aggregation. Thirteen well trained athletes performed a progressive and maximal exercise test during which blood was sampled at rest, at 50% of maximal exercise, and at maximal exercise. RBC aggregation was assessed with the Myrenne aggregometer which gives two indexes of RBC aggregation: “M” (aggregation during stasis after shearing at 600 s−1) and “M1” (facilitated aggregation at low shear rate after shearing at 600 s−1). A part of the resting blood sample was also reserved to test the in vitro effects of three lactate concentrations (2, 4 and 10 mM). The lactate solutions were described in a previous study (P. Connes, D. Bouix, G. Py, C. Préfaut, J. Mercier, J.F. Brun and C. Caillaud, Opposite effects of in vitro lactate on erythrocyte deformability in athletes and untrained subjects, Clin. Hemorheol. Microcirc. 31 (2004), 311–318). The results demonstrated that M and M1 were unchanged with exercise and lactate. Therefore, lactate is able to change RBC deformability but not RBC aggregation.
