title: Urinary myoglobin quantification by high-performance liquid chromatography: An alternative measurement for exercise-induced muscle damage.
abstract: This study investigated a means of quantifying urinary myoglobin using a novel reverse-phase high-performance liquid chromatography (RP-HPLC) method that is an alternative measure of exercise-induced muscle damage. It also investigated the effect of storage and alkalization on urinary myoglobin stability issues. An RP-HPLC method was validated by precision and repeatability experiments. Myoglobin stability was determined through spiked urine samples stored at various temperatures over an 8-week period using alkalization and dilution in a pH 7.0 buffer. The method was validated with urine collected from mixed martial arts fighters during a competition and training session. The method produced linearity from 5 to 1000 μg/ml (R(2) = 0.997), intra- and inter-assay coefficients of variation from 0.32 to 2.94%, and a lower detection limit of 0.2 μg/ml in the final dilution and 2 μg/ml in the original urine sample. Recovery ranged from 96.4 to 102.5%, myoglobin remained stable at 4 °C when diluted in a pH 7.0 buffer after 20 h, and a significant increase (P < 0.01) and an identifiable peak were observed following a mixed martial arts contest and training session. Storage length and conditions had significant effects (P < 0.05) on stability. The method's simplicity and noninvasive nature means it can be used as an alternative muscle damage assay following exercise and trauma.
authors.affiliation: Free Radical Biochemistry Laboratory, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.
authors.forename: Angus
authors.initials: A
authors.lastname: Lindsay
authors.affiliation: Free Radical Biochemistry Laboratory, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand.
authors.forename: Sam
authors.initials: S
authors.lastname: Carr
authors.affiliation: College of Life and Natural Sciences, University of Derby, Derby DE22 1GB, UK.
authors.forename: Nick
authors.initials: N
authors.lastname: Draper
authors.affiliation: Free Radical Biochemistry Laboratory, School of Biological Sciences, University of Canterbury, Christchurch 8140, New Zealand; Department of Radiology, University of Otago, Christchurch 8011, New Zealand. Electronic address: steven.gieseg@canterbury.ac.nz.
authors.forename: Steven P
authors.initials: SP
authors.lastname: Gieseg
mesh_terms: D000328:Adult; D002851:Chromatography, High Pressure Liquid; D056148:Chromatography, Reverse-Phase; D015444:Exercise; D006801:Humans; D018482:Muscle, Skeletal / Q000378:metabolism*; D009211:Myoglobin / Q000032:analysis*; D016482:Urinalysis / Q000379:methods*; D055815:Young Adult
chemical_list: D009211:Myoglobin
keywords: Exercise; HPLC; Mixed martial arts; Muscle damage; Myoglobin; Stability