ALM Therapy Promotes Functional and Histologic Regeneration of Traumatized Peripheral Skeletal Muscle

Simple Summary Skeletal muscle injuries are very common in everyday life and especially in sports. In most cases, these injuries can be treated conservatively and rarely require surgical therapy. Adenosine, lidocaine and Mg2+ (ALM) is a novel solution that has already achieved promising results in experimental studies. Among other things, ALM is cardioprotective and pulmoprotective and improves oxygenation. Our purpose was to determine whether ALM also has protective effects on traumatized peripheral skeletal muscle. Seventy male Wistar rats were anesthetized and subjected to standardized open skeletal muscle trauma. Standardized contusion was performed with the protection of the neurovascular structures. Subsequently, the experimental animals were randomly assigned to the saline control and ALM group and received intravenous infusions of saline or ALM. After 1, 4, 7, 14 and 42 days, the biomechanical regenerative capacity was examined using incomplete tetanic force and tetany. In addition, muscle tissue was assessed for proliferation and apoptosis characteristics by immunohistochemistry. After ALM therapy, biomechanical force development and cell behavior showed significant benefits. More proliferative cells and fewer apoptotic cells were detectable in ALM-treated animals. This indicates that traumatized skeletal muscle could be positively affected by ALM therapy. ALM could be considered in the future as an adjuvant therapy option in clinical practice. Skeletal muscle trauma is a common injury with a range of severity. Adenosine, lidocaine and Mg2+ (ALM) is a protective solution and improves tissue perfusion and coagulopathy. Male Wistar rats were anesthetized and subjected to standardized skeletal muscle trauma of the left soleus muscle with the protection of the neurovascular structures. Seventy animals were randomly assigned to saline control or ALM. Immediately after trauma, a bolus of ALM solution was applied intravenously, followed by a one-hour infusion. After 1, 4, 7, 14 and 42 days, the biomechanical regenerative capacity was examined using incomplete tetanic force and tetany, and immunohistochemistry was used to examine for proliferation and apoptosis characteristics. Biomechanical force development showed a significant increase following ALM therapy for incomplete tetanic force and tetany on days 4 and 7. In addition, the histological evaluation showed a significant increase in proliferative BrdU-positive cells with ALM therapy on days 1 and 14. Ki67 histology also detected significantly more proliferative cells on days 1, 4, 7, 14 and 42 in ALM-treated animals. Furthermore, a simultaneous decrease in the number of apoptotic cells was observed using the TUNEL method. ALM solution showed significant superiority in biomechanical force development and also a significant positive effect on cell proliferation in traumatized skeletal muscle tissue and reduced apoptosis.

Automated summary

Skeletal muscle injuries are common and often do not require surgery. ALM therapy, a novel solution, has shown promising results in improving muscle regeneration and reducing cell apoptosis. This study confirms the protective effects of ALM on traumatized skeletal muscle, suggesting that it could be a useful adjunct therapy option in clinical practice.