Lactate-transport activity in RBCs of trained and untrained individuals from four racing species.

The research paper investigates the differences in lactate-transport activities in the red blood cells of four types of athletic species: reindeer, horses, humans, and dogs. The study finds that this activity varies across these species, with no correlation to athleticism, and is affected differently by training in different species.

Lactate Transport in Different Species

• The study begins by collecting blood samples from 21 reindeer, 40 horses, 31 humans, and 38 dogs to analyze the activity of lactate transport within their red blood cells (RBCs).
• Lactate transport is crucial for athletes as during intense physical activity, the body produces more lactate, a product of glucose metabolism, and the transport of this lactate is crucial in regulating the body’s energy and pH balance.
• The lactate-transport activity is measured at two concentrations of lactate – 10 and 30 mM.

Role of Transporters

• The study also investigates the roles of two key transporters for lactate – the monocarboxylate-transporter (MCT) and the inorganic anion-exchange transporter, known as the band-3 protein.
• These transporters work to move lactate across the cell membrane of the red blood cells, and their activity is observed with the use of inhibitors to study their individual roles.

Results and Observations

• In reindeer and a third of horses, the lactate transport activity was found to be low, mainly facilitated by the band-3 protein and nonionic diffusion.
• In humans, dogs, and the remaining two-thirds of horses, the lactate transport activity was high and primarily mediated by the MCT.
• Interestingly, the study found no correlation between MCT activity and the athletic capability of the tested species. This suggests that other factors may influence athletic performance beyond lactate transport activity.

Impact of Training

• The study also explores the impact of training on lactate transport activity.
• In horses and humans, training had no discernible effect on lactate transport. But in reindeer and sled dogs, training actually increased total lactate transport.
• This finding is of great relevance to the training regimens of these species, suggesting that training can have physiological effects on lactate management in the body.

Conclusion

• The findings demonstrate that the distribution of lactate-transport activity varies across different species and it was only bimodal in horses.
• The researchers highlight the need for further studies, especially in horses, to better understand the link between RBC lactate and performance capacity.