title: Phosphorylase deficiency associated with isometric exercise intolerance.
abstract: In the patient reported here, most of the clinical and biochemical correlates of McArdle's disease were present; however, symptoms developed after isometric rather than after isotonic exercise. Histochemical reactions and assay of muscle homogenates confirmed the absence of phosphorylase; however, venous serum lactate increased in the arm after isometric and isotonic ischemic exercise, although the increase was significantly less than in a normal control. Although the symptoms differ significantly from those in McArdle's disease, this disorder could be a variant.
mesh_terms: D000328:Adult; D005260:Female; D006801:Humans; D009132:Muscles / Q000201:enzymology; D009135:Muscular Diseases / Q000201:enzymology*; D006005:Phosphorylases / Q000172:deficiency*; D005082:Physical Exertion
chemical_list: D006005:Phosphorylases