Platelet Lysate Enhances Equine Skeletal Muscle Regeneration in A Bupivacaine-Induced Muscle Injury Model☆.

The researchers studied the effect of platelet lysate (PL) on repairing muscle injuries in thoroughbred horses and found that administering PL led to a higher level of gene expression related to muscle repair and more noticeable regeneration of muscle morphology within 6 days of treatment.

About the study

• The study aimed to understand the impact of platelet lysate (PL) on the repair process of muscle injuries in thoroughbred horses. Muscle injuries were intentionally induced using bupivacaine in 26 horses, after which either PL or saline was administered the following day.
• Muscle samples were collected from 22 horses at different stages post-injury – day 2, 3, 4, and 7. The researchers assessed the concentration of growth factors and the level of gene expression related to muscle regeneration in these samples.
• For comparison purposes, samples before the injury were collected, and samples were also taken from injured horses that did not receive PL or saline treatment (sham samples).
• From the remaining 4 horses, samples were collected through surgical incision after euthanasia at 5 and 7 days post-injury. These samples were used for histological analysis.

Key Findings

• Platelet Lysate administration resulted in increased levels of growth factors, which were observed for up to one day post-administration. Moreover, the level of gene expressions related to muscle regeneration was boosted for up to 6 days post-administration.
• Interestingly, at 5 days post-injury, the number of muscle fibers expressing the embryonic myosin heavy chain – a protein marker for muscle regeneration – was significantly higher in the PL-treated horses compared to those treated with saline.
• However, by day 7 post-injury, there was no observable difference in the number of muscle fibers between both groups. It suggests a more rapid initiation of muscle regeneration in the PL group but overall similar rates of muscle fiber production.
• Additionally, the researchers noted that while the levels of muscle regeneration associated gene expressions remained high after PL administration, the growth factor levels from PL at the injection site dwindled by roughly 2 days post-administration.

Conclusion

• From this study, it can be concluded that platelet lysate administration can beneficially influence muscle repair following an injury by augmenting the expression of several genes associated with muscle regeneration and favoring morphological regeneration within the first week of treatment.