title: Cardiac troponin T and creatine kinase MB content in skeletal muscle of the uremic rat.
abstract: BACKGROUND
  The assertion that creatine kinase MB (CK-MB) and the developmental isoforms of cardiac troponin T (cTnT) are expressed by skeletal muscle in some clinical settings is an extrapolation from nonuremic rodent studies. We studied the content of CK-MB and cTnT in skeletal muscle of the renal-insufficient rat.
  
  
  METHODS
  Skeletal muscles (gastrocnemius) were collected from both five-sixths nephrectomized rats (n = 11) and sham-operated controls (n = 11). cTnT content was analyzed by Elecsys (Roche), immunoblotting, and immunohistochemistry with antibodies M7 and M11-7 (Roche). CK isoenzymes were analyzed electrophoretically.
  
  
  RESULTS
  Trace concentrations of cTnT were detected in some of the skeletal muscle samples [controls (3 of 11) and uremic rats (1 of 11)] at concentrations <0.01% of that detected in heart. By contrast, positive staining appeared in both groups with M11-7 by immunoblotting and immunohistochemistry. No immunoreactivity was detected in skeletal muscle using M7 in the immunoblot format, although immunoreactivity was detected by immunohistochemistry in all samples. The median percentages of CK-MB were 6.0% and 4.1% for the skeletal muscle from control and uremic rats, respectively.
  
  
  CONCLUSIONS
  The detection of cTnT and CK-MB in skeletal muscle does not differ for uremic rats compared with sham-operated controls. cTnT isoforms detected by qualitative methods are not detected with the cTnT immunoassay. Observations with rodents should not necessarily be extrapolated to humans.
authors.affiliation: Analytical Unit, Cardiological Sciences, St. George's Hospital Medical School, London SW17 0RE, United Kingdom. frederic@sghms.ac.uk
authors.forename: Salim
authors.initials: S
authors.lastname: Fredericks
authors.forename: Joanne F
authors.initials: JF
authors.lastname: Murray
authors.forename: Nicholas D
authors.initials: ND
authors.lastname: Carter
authors.forename: Alistair M S
authors.initials: AM
authors.lastname: Chesser
authors.forename: Stavroula
authors.initials: S
authors.lastname: Papachristou
authors.forename: Magdi M
authors.initials: MM
authors.lastname: Yaqoob
authors.forename: Paul O
authors.initials: PO
authors.lastname: Collinson
authors.forename: David
authors.initials: D
authors.lastname: Gaze
authors.forename: David W
authors.initials: DW
authors.lastname: Holt
mesh_terms: D000818:Animals; D015153:Blotting, Western; D003402:Creatine Kinase / Q000378:metabolism*; D052279:Creatine Kinase, MB Form; D007150:Immunohistochemistry; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D018482:Muscle, Skeletal / Q000201:enzymology / Q000378:metabolism*; D009392:Nephrectomy; D051381:Rats; D017208:Rats, Wistar; D020107:Troponin T / Q000378:metabolism*; D014511:Uremia / Q000201:enzymology / Q000378:metabolism*
chemical_list: D007527:Isoenzymes; D020107:Troponin T; D003402:Creatine Kinase; D052279:Creatine Kinase, MB Form