Role of α-actin in muscle damage of injured athletes in comparison with traditional markers

Abstract

Objective: In order to identify a reliable marker for the early detection of muscle injuries in sports, a-actin protein and other markers of muscle damage were studied in sera of uninjured sportspeople and those with skeletal muscle injury. Methods: Blood samples were obtained from 20 sportspeople with skeletal muscle injury and 48 uninjured sportspeople. Immunoassays were performed to determine cardiac troponin I (TnI), troponin T, lactate dehydrogenase and myoglobin concentrations. Western blot and densitometry were used to measure a-actin concentrations. Skeletal muscle damage was diagnosed according to physical examination, MRI findings and the biochemical criterion of a creatine kinase value .500 IU/l (Rosalki method, Beckman Instruments SL, Fullerton, California, USA). Results were also compared with previously obtained data on injured and uninjured non-sportspeople. Results: The mean serum concentration of a-actin was significantly higher in sportspeople with muscle damage (10.49 mg/ml) than in uninjured sportspeople (3.99 mg/ml). Sera from injured sportspeople showed higher levels of a-actin than of troponin or myoglobin. No significant difference in TnI levels was observed between the groups. Conclusions: According to these results, a-actin is a new and reliable marker of skeletal muscle damage in sportspeople which can be used for the detection of muscle injury. Possible cross interference between skeletal and cardiac muscle damage can be discriminated by the combined use of a-actin and TnI. These data suggest that early measurement of a-actin in sportspeople with suspected muscle damage will allow them to receive earlier and more effective treatment and to return sooner to the practice of their sport.

Diagnosis and prognosis of acute hamstring injuries in athletes

“…More research is needed to determine the real diagnostic and prognostic value of potential markers, such as ‘fast myosin heavy chains’ (fast MHC) [26], ‘skeletal-troponin I’ (sTnI) [55] and ‘alfa-actin’ [40]. …”

MALDI imaging mass spectrometry: Discrimination of pathophysiological regions in traumatized skeletal muscle by characteristic peptide signatures

“…An altered Acta1 gene expression associated with the loss of contractile muscle mass was observed by other groups investigating degeneration in human rotator cuff muscles . Moreover, the release of Acta1 into the blood stream after skeletal muscle damage has been observed in animals and humans .…”

Plasma Actin, Gelsolin and Orosomucoid Levels after Eccentric Exercise

“…Amat et al (2007) described earlier that only muscle trauma or lesions caused major actin release into the circulation, so it is possible that plasma actin might be useful for the distinction between micro injuries as well as severe muscle damages and lesions. Supporting this idea, we did not detect any relationship between the plasma actin level and CK or the muscle soreness score.…”

“…Later, Amat et al (2007) found higher α -actin levels in athletes with skeletal muscle lesions versus healthy athletes, suggesting that α -actin concentration might be sensitive to EIMD in athletes. In contrast, Féasson et al (2002) reported that the amount of α -actin remained unchanged immediately, 1 and 14 days after downhill treadmill running.…”