[cAMP-dependent phosphorylation of myocardial troponin in experimental myocardial infarction]

cAMP-dependent phosphorylation of troponin, content of cAMP and the rate of the protein kinase complex activation were studied in dog heart muscle under conditions of experimental myocardial infarction. Incorporation of 32P into troponin I as well as the content of the cyclic nucleotide were shown to decrease in the impaired muscles as compared with the normal heart muscle. In experimental myocardial infarction the rate of the protein kinase complex dissociation appears to be altered as suggested by the fact that adrenaline stimulated dissimilarly the activity of cAMP-dependent protein kinase in vitro in presence and in absence of cAMP both in the intact and necrotized muscles.