Monocarboxylate transporters (MCT) as lactate carriers in equine muscle and red blood cells.

The study investigated the role of monocarboxylate transporters (MCT) in the translocation of lactate in horse muscles and red blood cells, and how these interactions might influence lactate accumulation during physical activity. It was found that the expression of these carriers can vary considerably, influencing lactate transport activities differently.

Objective of the Study

• The research aimed to study the expression of MCT isoforms (MCT1, MCT2 and MCT4) and their relationship with the helper protein CD147 in the middle gluteal muscle of horses.

Methods Employed

• Researchers collected venous blood and muscle biopsy samples from 14 Standardbred horses.
• Their lactate transport activity in their red blood cells was assessed, and the amounts of MCT1, 2, 4, and CD147 were measured.

Results

• Scientists discovered MCT1, MCT4, and CD147 within the horse muscles.
• The quantity of MCT1 presented varied and was not influenced by factors such as age or training.
• The expression of MCT4 increased with age and showed positive correlation with CD147.
• CD147 in horse muscle was found to correlate with CD147 in red blood cells.
• The quantities of MCT4 in muscle and the ratio of CD147/MCT1 in red blood cells were higher in race fit horses compared to moderately trained horses.

Conclusions

• Researchers found that the MCT isoform profile in horse muscle was similar to that in humans.
• They suggested that lactate transport activity in muscles may vary among individuals, as it does with red blood cells, based on the correlation found between CD147 in muscle and red blood cells.
• They also conclude by noting that a larger number of horses would need to be tested to confirm the relationship between CD147 in muscle and red blood cells, and to establish lactate transport activity in red blood cells as a reliable indicator of the respective activity in muscles.