title: Accumulation of CK-MM is impaired in innervated and contracting cultured muscle fibers of Duchenne muscular dystrophy patients.
abstract: No specific abnormalities have been reproducibly manifested in aneurally cultured muscle of Duchenne muscular dystrophy (DMD) patients. We now report that the accumulation of the muscle-"specific" isozyme of creatine kinase (CK-MM) was significantly and preferentially impaired in long-term innervated contracting muscle fibers cultured from 4 DMD patients (DMD-InnCMFs) compared to: i) their noninnervated sister-cultured muscle fibers, and ii) innervated contracting control cultured human muscle fibers (Control-InnCHMFs). Accumulation of other muscle-"specific" isozymes (MSIs), viz. glycogen phosphorylase, phosphoglycerate mutase, and lactic dehydrogenase, was not significantly impaired. We have not observed preferentially-impaired CK-MM accumulation in any Control-InnCHMFs from 22 patients (children and adults) with a variety of neuromuscular diseases. There was no apparent difference between DMD-InnCMFs and Control InnCHMFs regarding: acceptance of innervation; neuronally-driven, virtually continuous muscle-fiber contractions; characteristic myofiber organization by phase-contrast microscopy, and increased longevity of the innervated fibers.
mesh_terms: D000818:Animals; D002648:Child; D003402:Creatine Kinase / Q000378:metabolism*; D046508:Culture Techniques / Q000379:methods; D005727:Ganglia, Spinal / Q000502:physiology*; D006801:Humans; D007527:Isoenzymes / Q000378:metabolism*; D008297:Male; D009119:Muscle Contraction; D009132:Muscles / Q000201:enzymology* / Q000294:innervation; D009136:Muscular Dystrophies / Q000201:enzymology* / Q000473:pathology; D009474:Neurons / Q000502:physiology; D051381:Rats
chemical_list: D007527:Isoenzymes; D003402:Creatine Kinase