title: Effects of fibre type and diffusion distance on mouse skeletal muscle glycogen content in vitro.
abstract: In vitro incubation of isolated rodent skeletal muscle is a widely used procedure in metabolic research. One concern with this method is the development of an anoxic state during the incubation period that can cause muscle glycogen depletion. Our aim was to investigate whether in vitro incubation conditions influence glycogen concentration in glycolytic extensor digitorum longus (EDL) and oxidative soleus mouse muscle. Quantitative immunohistochemistry was applied to assess glycogen content in incubated skeletal muscle. Glycogen concentration was depleted, independent of insulin-stimulation in the incubated skeletal muscle. The extent of glycogen depletion was correlated with the oxidative fibre distribution and with the induction of hypoxia-induced-factor-1-alpha. Insulin exposure partially prevented glycogen depletion in soleus, but not in EDL muscle, providing evidence that glucose diffusion is not a limiting step to maintain glycogen content. Our results provide evidence to suggest that the anoxic milieu and the intrinsic characteristics of the skeletal muscle fibre type play a major role in inducing glycogen depletion in during in vitro incubations.
authors.affiliation: Department of Molecular Medicine and Surgery, Section of Integrative Physiology, Karolinska Institutet, Stockholm, Sweden.
authors.forename: Peter
authors.initials: P
authors.lastname: Sogaard
authors.forename: Ferenc
authors.initials: F
authors.lastname: Szekeres
authors.forename: Maria
authors.initials: M
authors.lastname: Holmström
authors.forename: Dennis
authors.initials: D
authors.lastname: Larsson
authors.forename: Mikael
authors.initials: M
authors.lastname: Harlén
authors.forename: Pablo
authors.initials: P
authors.lastname: Garcia-Roves
authors.forename: Alexander V
authors.initials: AV
authors.lastname: Chibalin
mesh_terms: D000818:Animals; D004058:Diffusion; D005947:Glucose / Q000378:metabolism; D006003:Glycogen / Q000032:analysis*; D000860:Hypoxia; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007328:Insulin / Q000494:pharmacology; D051379:Mice; D018485:Muscle Fibers, Skeletal / Q000737:chemistry*; D010084:Oxidation-Reduction; D046509:Tissue Culture Techniques / Q000379:methods*
chemical_list: C497443:Hif1a protein, mouse; D051795:Hypoxia-Inducible Factor 1, alpha Subunit; D007328:Insulin; D006003:Glycogen; D005947:Glucose