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Increased muscular β‐hydroxyacyl CoA dehydrogenase with McArdle's disease
Author(s) -
Turk William R.,
Heller Scott L.,
Norris Beverly J.,
Nemeth Patti M.
Publication year - 1990
Publication title -
muscle and nerve
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.025
H-Index - 145
eISSN - 1097-4598
pISSN - 0148-639X
DOI - 10.1002/mus.880130708
Subject(s) - glycogen phosphorylase , glycogen , glycolysis , dehydrogenase , oxidative phosphorylation , medicine , biochemistry , glycogen storage disease , endocrinology , enzyme , beta oxidation , glycogen debranching enzyme , metabolic pathway , citric acid cycle , biology , chemistry
Enzymes of energy production were measured in muscle homogenates and in individual muscle fibers from 5 patients with McArdle's disease. Individual fibers were investigated to determine whether fibers of all types were completely devoid of glycogen phosphorylase activity and whether the involved fibers might be biochemically altered in a fiber type dependent manner to enhance the energy‐generating capabilities of the cells through other metabolic pathways. Using highly sensitive biochemical assays, a complete absence of glycogen phosphorylase, a and b, activity was found in fibers of all types in the McArdle's patients. Levels of enzymes representing glycolysis, the Krebs cycle, and high energy phosphate metabolism were essentially normal in each fiber type, indicating an apparent lack in metabolic adaptation of these energy pathways to the absence of fatty acids (β‐hydrosyacyl CoA dehydrogenase, βOAC) was elevated in all patients, and substantially in 4 of the 5. This suggested that lipid substrates can provide support for oxidative endurance capacity in some patients. Individual fiber analysises indicated that the compensation involved fibers of all types.