title: Metabolic profiling of heat or anoxic stress in mouse C2C12 myotubes using multinuclear magnetic resonance spectroscopy.
abstract: In the present study, the metabolic effects of heat and anoxic stress in myotubes from the mouse cell line C2C12 were investigated by using a combination of (13)C, (1)H, and (31)P nuclear magnetic resonance (NMR) spectroscopy and enrichment with [(13)C]-glucose. Both the (13)C and the (1)H NMR spectra showed reduced levels of the amino acids alanine, glutamate, and aspartate after heat or anoxic stress. The decreases were smallest at 42 degrees C, larger at 45 degrees C, and most pronounced after anoxic conditions. In addition, in both the (1)H and the (31)P NMR spectra, decreases in the high-energy phosphate compounds adenosine triphosphate and phosphocreatine with increasing severity of stress were identified. At anoxic conditions, an increase in (13)C-labeled lactate and appearance of glycerol-3-phosphate were observed. Accumulation of lactate and glycerol-3-phosphate is in agreement with a shift to anaerobic metabolism due to inhibition of the aerobic pathway in the mitochondria. Conversely, lower levels of unlabeled ((12)C) lactate were apparent at increasing severity of stress, which indicate that lactate is released from the myotubes to the medium. In conclusion, the metabolites identified in the present study may be useful markers for identifying severity of stress in muscles.
authors.affiliation: Department of Food Science, Faculty of Agricultural Sciences, University of Aarhus, P.O. 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: Bent O
authors.initials: BO
authors.lastname: Petersen
authors.forename: Jens Ø
authors.initials: JØ
authors.lastname: Duus
authors.forename: Niels
authors.initials: N
authors.lastname: Gregersen
authors.forename: Peter
authors.initials: P
authors.lastname: Bross
authors.forename: Niels
authors.initials: N
authors.lastname: Oksbjerg
authors.forename: Hanne C
authors.initials: HC
authors.lastname: Bertram
mesh_terms: D000244:Adenosine Diphosphate / Q000378:metabolism; D000596:Amino Acids / Q000378:metabolism; D000818:Animals; D015415:Biomarkers; D002460:Cell Line; D003627:Data Interpretation, Statistical; D005994:Glycerophosphates / Q000378:metabolism; D018882:Heat Stress Disorders / Q000378:metabolism*; D000860:Hypoxia / Q000378:metabolism*; D019344:Lactic Acid / Q000378:metabolism; D009682:Magnetic Resonance Spectroscopy; D051379:Mice; D008931:Mitochondria, Muscle / Q000378:metabolism; D018485:Muscle Fibers, Skeletal / Q000737:chemistry / Q000378:metabolism*; D018482:Muscle, Skeletal / Q000737:chemistry / Q000378:metabolism*; D032446:Myoblasts / Q000378:metabolism; D010725:Phosphocreatine / Q000097:blood; D013696:Temperature
chemical_list: D000596:Amino Acids; D015415:Biomarkers; D005994:Glycerophosphates; D010725:Phosphocreatine; D019344:Lactic Acid; D000244:Adenosine Diphosphate