Interindividual variation in total and carrier-mediated lactate influx into red blood cells.

The research article investigates the variation in lactate influx into red blood cells in horses and identifies different transporters involved in the process.

Objective and Methodology

• The main aim of this research was to study the variation in the influx of lactate into red blood cells among different horses. Lactate is a product of metabolism that needs to be transported in and out of cells for maintaining cellular homeostasis.
• The researchers collected blood samples from 89 standardbred horses of varying ages (from 2 weeks to 9 years) to conduct this study.

Findings and Interpretation

• The rate of lactate influx was studied and two groups of horses were found. In the first group of 62 horses, the average rate was around 4.09 nmol.mg protein-1.min-1 at a lactate concentration of 10 mM. In the second group of 27 horses, the rate was significantly lower at 0.58 nmol.mg protein-1.min-1 at the same concentration of lactate. This group division did not depend on the horses’ age. In other words, the study discovered a bimodal distribution.
• When the lactate concentration in the medium was increased to 30 mM, the rates of influx for the two groups were 8.71 and 1.97 nmol.mg protein-1.min-1, respectively, exhibiting a similar difference between the two groups.
• In the group with higher lactate transport activity, the monocarboxylate transporter (MCT) was identified as a main carrier. In the group with low transport activity, no activity of the MCT was detected.
• The protein known as band 3 was also identified as potentially being responsible for 18-39% of the transport activity. This protein acts as an anion exchange protein, helping in the transportation of molecules like lactate in and out of the cells.
• The study also indicated that the lactate transport activity tended to be higher in female horses (mares) compared to male horses (stallions) across all age groups.

Conclusion

• The study concludes that the transport of lactate into red blood cells is an inherent process, and it varies among individual horses. They also noted the involvement of multiple transport carriers and proteins varies among individual horses.