Abstract
Background: Detection of skeletal muscle injury is hampered by a lack of commercially available assays for serum markers specific for skeletal muscle; serum concentrations of skeletal troponin I (sTnI) could meet this need. Moreover, because sTnI exists in 2 isoforms, slow (ssTnI) and fast (fsTnI), corresponding to slow- and fast-twitch muscles, respectively, it could provide insight into differential injury/recovery of specific fiber types. The purpose of this study was to investigate whether the 2 isoforms of sTnI and their modified forms are present in the blood of patients with various skeletal muscle disorders. Methods: Serial serum samples were obtained from 25 patients with various skeletal muscle injuries. Serum proteins were separated by a modified sodium dodecyl sulfate-polyacrylamide gel electrophoresis protocol followed by Western blotting for sTnI with monoclonal antibodies specific to ssTnI and fsTnI. Results: We observed (a) intact and, in some cases, degraded sTnI products; (b) evidence of posttranslational modifications in addition to proteolysis; and (c) differential detectability of both skeletal isoforms in the same patient. Conclusions: It is possible to monitor both sTnI isoforms; this could lead to the development of new diagnostic assays for skeletal muscle damage.
Original language | English (US) |
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Pages (from-to) | 966-972 |
Number of pages | 7 |
Journal | Clinical chemistry |
Volume | 51 |
Issue number | 6 |
DOIs | |
State | Published - Jun 2005 |
Externally published | Yes |
ASJC Scopus subject areas
- Clinical Biochemistry
- Biochemistry, medical