[The possible role of disruptions of the cyclic AMP system in the pathogenesis of thyrotoxic myopathies].

The value of kdiss of the "proteinkinase-cAMP" complex was increased 1.8-fold, number of the nucleotide binding sites was increased 3.7-fold with simultaneous decrease in cAMP concentration, when the cyclase system was studied in skeletal muscles of mice with experimental thyrotoxic myopathy. Activities of phosphodiesterase, adenylate cyclase, rate of activation of adenylate cyclase by adrenaline and sodium fluoride did not significantly differ as compared with normal values. Impairment of hormonal regulation of the cAMP-dependent processes is apparently responsible for multiple molecular and structural injuries in skeletal muscles in thyrotoxicosis.