title: NMR-based metabonomic investigation of heat stress in myotubes reveals a time-dependent change in the metabolites.
abstract: NMR-based metabonomics was applied to elucidate the time-dependent stress responses in mouse myotubes after heat exposure of either 42 or 45 degrees C for 1 h. Principal component analysis (PCA) revealed that the gradual time-dependent changes in metabolites contributing to the clustering and separation of the control samples from the different time points after heat stress primarily are in the metabolites glucose, leucine, lysine, phenylalanine, creatine, glutamine, and acetate. In addition, PC scores revealed a maximum change in metabolite composition 4 h after the stress exposure; thereafter, samples returned toward control samples, however, without reaching the control samples even 10 h after stress. The results also indicate that the myotubes efficiently regulate the pH level by release of lactate to the culture medium at a heat stress level of 42 degrees C, which is a temperature level reached in muscles of pigs during exposure to slaughter stress.
authors.affiliation: Department of Food Science, Faculty of Agricultural Sciences, Aarhus University, Blichers Alle 20, PO Box 50, DK-8830 Tjele, Denmark.
authors.forename: Ida K
authors.initials: IK
authors.lastname: Straadt
authors.forename: Jette F
authors.initials: JF
authors.lastname: Young
authors.forename: Peter
authors.initials: P
authors.lastname: Bross
authors.forename: Niels
authors.initials: N
authors.lastname: Gregersen
authors.forename: Niels
authors.initials: N
authors.lastname: Oksbjerg
authors.forename: Peter K
authors.initials: PK
authors.lastname: Theil
authors.forename: Hanne C
authors.initials: HC
authors.lastname: Bertram
mesh_terms: D000596:Amino Acids / Q000032:analysis; D000818:Animals; D002460:Cell Line; D002478:Cells, Cultured; D005947:Glucose / Q000032:analysis; D018840:HSP70 Heat-Shock Proteins / Q000235:genetics; D006358:Hot Temperature; D006863:Hydrogen-Ion Concentration; D019344:Lactic Acid / Q000032:analysis; D009682:Magnetic Resonance Spectroscopy; D055432:Metabolomics; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000737:chemistry / Q000378:metabolism*; D012333:RNA, Messenger / Q000032:analysis; D013552:Swine; D013997:Time Factors
chemical_list: D000596:Amino Acids; D018840:HSP70 Heat-Shock Proteins; D012333:RNA, Messenger; D019344:Lactic Acid; D005947:Glucose