[Defects in the cyclic adenosine monophosphate system--new hypothesis for the etiology and development of the myodystrophic process].

The role of the cyclic nucleotides in the development of myodystrophic process is demonstrated. It has been shown that in patients with X-chromosome-linked myopathies the metabolic defect is localized at the level of adenylcyclase (AC): this leads to a drop of the content of cyclic adenosine monophosphate (cAMP) in the muscular tissue below the threshold magnitudes of activation of protein kinases (PKs). Indications of the primary character of those changes are: absence of relationship between the degree of the enzyme activity disturbance and the disease stage; discovery of this defect in heterozygotic carriers and systemic character of the AC complex affection. In cases of autosomal myodystrophies the primary defect of the mutant gene manifests itself in an imitation of a rise of the cAMP level because of the structural peculiarities of PKs. The data obtained were used as the basis for developing an essentially new method of treating autosomal forms of neuromuscular diseases.