Effects of bone fracture and surgery on plasma myosin heavy chain fragments of skeletal muscle.
OBJECTIVE
Myosin heavy chain (MHC) fragment is part of a structural or force-bearing protein expressed in the thick filament of muscle fibres. Since MHC fragment is a contractile protein, an increase in plasma MHC concentrations after muscle injury indicates degradation of the contractile apparatus. This study was conducted to determine whether MHC concentrations could be a tool in the assessment of tissue damage in patients with myoskeletal injuries.


METHODS
Prospective, controlled study.


METHODS
A UK University National Health Service Centre.


METHODS
Thirty-eight orthopedic patients, of whom 14 received surgical treatments within the 2-day study period. Patients were compared with 16 nonorthopedic control subjects.


METHODS
Serum levels of MHC, creatine kinase, cardiac troponin I (cTnI), and myoglobin were measured at the time of admission and 24 hours later. Data from patients undergoing surgical repairs were obtained 24 hours after surgery. A competitive radio-immunoassay for beta-type MHC was used.


RESULTS
Plasma MHC concentration was higher in the patients than in the controls. The peak levels were observed 24 hours after injury or surgery (p < 0.05). cTnI concentrations were consistently below the assay detection limit of 0.3 microgram/L, thus excluding protein release from the heart muscle (cardiac beta-type MHC). Creatine kinase and myoglobin concentrations were significantly higher on admission in the non-surgical patients than in the surgically treated cases.


CONCLUSIONS
Serum MHC levels could be a useful supplementary retrospective, prognostic or diagnostic tool in the study of myoskeletal disturbances involving muscle injury or bone fractures that result in membrane leakage of myoskeletal cells.
Onuoha
G N
GN
Department of Surgery, School of Medicine, University of Birmingham, Edgbaston, England.
Alpar
E K
EK
Laprade
M
M
Rama
D
D
Pau
B
B
D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D003402:Creatine Kinase / Q000097:blood; D005260:Female; D050723:Fractures, Bone / Q000097:blood / Q000601:surgery*; D006801:Humans; D008297:Male; D008875:Middle Aged; D018482:Muscle, Skeletal / Q000098:blood supply / Q000293:injuries*; D009211:Myoglobin / Q000097:blood; D018995:Myosin Heavy Chains / Q000097:blood*; D011446:Prospective Studies; D019210:Troponin I / Q000097:blood
D015415:Biomarkers; D009211:Myoglobin; D019210:Troponin I; D003402:Creatine Kinase; D018995:Myosin Heavy Chains