Factors affecting accumulation of lactate in red blood cells

Abstract

Summary In horses, both the post exercise distribution of lactate between plasma and red blood cells (RBC) and the activity of lactate transporters on the RBC membrane vary widely between individuals. In this study, we investigated the effects of pH, time and temperature on lactate distribution in vitro, and compared the in vitro activity of lactate transporters with the accumulation of lactate into RBC in vivo. To accomplish this, we took venous blood samples at rest and after trotting races. The post exercise accumulation of lactate into RBC was shown to depend on the activity of lactate transporters. The results, in vitro, also indicate that pH, incubation time and temperature influence the activity of lactate transporters and the accumulation of lactate into RBC, underscoring the fact that in practice it is important to standardise the measurement conditions of lactate. These results support the view that whole blood lactate concentrations should be measured in estimating the accumulation of lactate from exercising muscles into the blood, because the effect of blood pH, temperature, time to centrifugation of the sample and also interindividual variation in lactate transport into RBC are therefore minimised.

Candidate genes for performance in horses, including monocarboxylate transporters

“…Up to 50% of the total lactate can be found in red blood cells of horses after intense exercise, and therefore, it is speculated that the red blood cells are responsible for re-ducing the concentration of blood lactate levels during maximal exercise (Pösö et al 1995, Väihkönen et al 1999. The lactate influx into the erythrocytes may be influenced by various factors and becomes greater with lower pH and increased temperature (Väihkönen et al 1999). Lactate can enter the erythrocytes by three routes (Poole & Halestrap 1993), (1) free diffusion of acids not dissociated, (2) monocarboxylate transporters (MCTs), or (3) protein band 3 (anion exchanger 1, AE1).…”

Age‐related changes and inheritance of lactate transport activity in red blood cells

“…Based on the results from previous studies (Väihkönen and Pösö 1998;Väihkönen et al 1999Väihkönen et al , 2001), horses were classified into 2 groups based on their lactate transport activity (nmol/mg x min) measured at 10 mmol/l lactate concentration; low (LT) activity with ≤ 1 and high (HT) activity with >1. In the sample, 24 of the 101 horses (24%) were classified as LT.…”

“…The role of MCT and AE1 in lactate transport can be studied by use of inhibitors (Skelton et al 1995;Väihkönen and Pösö 1998;Väihkönen et al 1999Väihkönen et al , 2001) and our previous studies have shown convincingly that interindividual variation is due to variation in MCT activity. The difference in transport activity is also reflected in vivo; after maximal exercise (trotting race), the lactate concentration in RBC of HT horses is higher than that of LT horses (Väihkönen et al 1999).…”

“…The main lactate carriers on the RBC membrane are the H + -monocarboxylate cotransporter (MCT) and the anion-exchange protein (AE1) (Poole and Halestrap 1993;Juel 1998). We have shown previously that, in Standardbred horses, lactate transport activity varies between individuals and, based on this activity, horses can be divided into 2 groups: low lactate transport (LT) and high lactate transport (HT) ( Väihkönen and Pösö 1998;Väihkönen et al 1999Väihkönen et al , 2001). The role of MCT and AE1 in lactate transport can be studied by use of inhibitors (Skelton et al 1995;Väihkönen and Pösö 1998;Väihkönen et al 1999Väihkönen et al , 2001) and our previous studies have shown convincingly that interindividual variation is due to variation in MCT activity.…”

“…We have shown previously that, in Standardbred horses, lactate transport activity varies between individuals and, based on this activity, horses can be divided into 2 groups: low lactate transport (LT) and high lactate transport (HT) ( Väihkönen and Pösö 1998;Väihkönen et al 1999Väihkönen et al , 2001). The role of MCT and AE1 in lactate transport can be studied by use of inhibitors (Skelton et al 1995;Väihkönen and Pösö 1998;Väihkönen et al 1999Väihkönen et al , 2001) and our previous studies have shown convincingly that interindividual variation is due to variation in MCT activity. The difference in transport activity is also reflected in vivo; after maximal exercise (trotting race), the lactate concentration in RBC of HT horses is higher than that of LT horses (Väihkönen et al 1999).…”