Pathogenesis of experimental thyrotoxic myopathy.
Focal degenerative changes of skeletal muscle fibers (decrease in mean diameter, excessive axonal branching and a decrease in the mean diameter of motor end-plates together with a reduction of their acetylcholinesterase levels) were found by means of the experimental model thyrotoxic myopathy in mice compared to controls. A decrease in protein kinase affinity to cAMP and an increase in the number of nucleotide binding sites were revealed with a simultaneous decrease in cAMP level. The weakening of hormonal control of cAMP-dependent processes is probably the basic cause of muscular weakness and structural changes in skeletal muscles in thyrotoxic myopathy.
D000110:Acetylcholinesterase / Q000378:metabolism; D000262:Adenylyl Cyclases / Q000378:metabolism; D000818:Animals; D001706:Biopsy; D001835:Body Weight; D000242:Cyclic AMP / Q000378:metabolism; D005260:Female; D006980:Hyperthyroidism / Q000150:complications* / Q000503:physiopathology; D051379:Mice; D009045:Motor Endplate / Q000201:enzymology; D009046:Motor Neurons / Q000648:ultrastructure; D009132:Muscles / Q000473:pathology; D009135:Muscular Diseases / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D010727:Phosphoric Diester Hydrolases / Q000378:metabolism; D011494:Protein Kinases / Q000378:metabolism
D000242:Cyclic AMP; D011494:Protein Kinases; D000110:Acetylcholinesterase; D010727:Phosphoric Diester Hydrolases; D000262:Adenylyl Cyclases