Lactate transport in red blood cells by monocarboxylate transporters.

This research paper examines the transportation of lactate in red blood cells among different horses and how it contributes to their performance during exercise. The researchers found that horses with high lactate transport activity showed a higher red blood cell lactate concentration, indicating a possible correlation between lactate transport capacity and performance abilities.

Study Objective and Methodology

• The main objective of this study was to understand the impact of lactate transport activity in red blood cells (RBC) of horses. The researchers wanted to explore if variations in this activity among horses could affect their performance capacity.
• In total, samples from ten horses were taken, of which 5 fall under the high transport (HT) category and 5 under low transport (LT).
• Blood and plasma lactate concentrations, lactate and pyruvate transport activities, and the amounts of H+-monocarboxylate co-transporter (MCT) 1, MCT2, and MCT4 were all measured in both the resting and post-submaximal exercise states of the horses.

Findings

• The findings of the study showed that post exercise, the RBC lactate concentration was higher in HT horses compared to those in the LT group.
• When at lactate concentrations of 0.25-30 mmol/l or a pyruvate concentration of 1 mmol/l, the transport activity was also found to be higher in HT horses whereas it was similar when lactate concentration was at 0.1 mmol/l.
• In the tests, the signals of MCT1 and MCT2 were found to be similar in both the groups however, the amount of CD147 – a chaperone necessary for the activity of MCT1 was lower in the LT group of horses.

Conclusions

• Based on these findings, the researchers suggest that MCT2 is responsible for transporting lactate at lower concentrations while MCT1 is needed at higher concentrations of lactate.
• The LT horses may have less active MCT1 and hence could have a reduced capacity to uptake lactate during exercise.
• Although the research provides significant insight into the lactate transport activity, further studies are still needed to fully understand whether the differences in lactate influx in red blood cells can impact the function of the cells themselves or the overall performance capacity of the horses.