title: Glycolytic potential and activity of adenosine monophosphate kinase (AMPK), glycogen phosphorylase (GP) and glycogen debranching enzyme (GDE) in steer carcasses with normal (<5.8) or high (>5.9) 24h pH determined in M. longissimus dorsi.
abstract: Muscle glycogen concentration (MGC) and lactate (LA), activity of glycogen debranching enzyme (GDE), glycogen phosphorylase (GP) and adenosine monophosphate kinase (AMPK) were determined at 0.5h (T0) and 24h (T24) post-mortem in Longissimus dorsi samples from 38 steers that produced high pH (>5.9) and normal pH (<5.8) carcasses at 24h postmortem. MGC, LA and glycolytic potential were higher (P<0.05) in normal pH carcasses. GDE activity was similar (P>0.05) in both pH categories. GP activity increased between T0 and T24 only in normal pH carcasses. AMPK activity was four times higher in normal pH v/s high pH carcasses, without changing its activity over time. Results reinforce the idea that differences in postmortem glycogenolytic/glycolytic flow in L. dorsi of steers showing normal v/s high muscle pH at 24h, could be explained not only by the higher initial MGC in normal pH carcasses, but also by a high and sustained activity of AMPK and an increased GP activity at 24h postmortem.
authors.affiliation: Programa Doctorado en Ciencias Veterinarias, Escuela de Graduados, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Chile.
authors.forename: A
authors.initials: A
authors.lastname: Apaoblaza
authors.affiliation: Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Chile.
authors.forename: A
authors.initials: A
authors.lastname: Galaz
authors.affiliation: Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Chile.
authors.forename: P
authors.initials: P
authors.lastname: Strobel
authors.affiliation: Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Chile.
authors.forename: A
authors.initials: A
authors.lastname: Ramírez-Reveco
authors.affiliation: Departamento de Zootecnia, Facultad de Agronomía, Universidad del Zulia Núcleo Agropecuario, Maracaibo, Venezuela.
authors.forename: N
authors.initials: N
authors.lastname: Jeréz-Timaure
authors.affiliation: Instituto de Ciencia Animal, Facultad de Ciencias Veterinarias, Universidad Austral de Chile, Chile. Electronic address: cgallo@uach.cl.
authors.forename: C
authors.initials: C
authors.lastname: Gallo
mesh_terms: D055372:AMP-Activated Protein Kinases / Q000378:metabolism*; D000249:Adenosine Monophosphate / Q000378:metabolism; D000255:Adenosine Triphosphate / Q000378:metabolism; D000818:Animals; D002417:Cattle; D006003:Glycogen / Q000378:metabolism*; D006004:Glycogen Debranching Enzyme System / Q000378:metabolism*; D024981:Glycogen Phosphorylase / Q000378:metabolism*; D006019:Glycolysis / Q000502:physiology*; D006801:Humans; D006863:Hydrogen-Ion Concentration; D008297:Male; D008460:Meat / Q000032:analysis*; D018482:Muscle, Skeletal / Q000737:chemistry / Q000201:enzymology; D010766:Phosphorylation
chemical_list: D006004:Glycogen Debranching Enzyme System; D000249:Adenosine Monophosphate; D000255:Adenosine Triphosphate; D006003:Glycogen; D024981:Glycogen Phosphorylase; D055372:AMP-Activated Protein Kinases
keywords: AMPK; Cattle; Glycogen; Glycolytic enzymes; Muscle pH