[Mechanism of disruption in the metabolism of the cyclic AMP system in myocardial tissue in allergic deterioration].

Role of hormones, guanylic nucleotides and sodium fluoride in regulation of adenylate cyclase activity was studied in rabbit heart under conditions of its allergic deterioration caused by repeated administration of horse blood serum. In the allergic injury activation of adenylate cyclase was found to occur simultaneously with a decrease in the rate of the enzyme stimulation by means of either the hormones in presence of guanylic nucleotides or by sodium fluoride. Without guanylic nucleotides the hormones did not stimulate adenylate cyclase activity. At the same time, under conditions of allergic sensitization the hormone stimulated adenylate cyclase was practically not activated by guanylic nucleotides. Unspecific desensitization of membrane receptors to hormones was responsible for impairments in regulation of adenylate cyclase activity under conditions of allergic sensitization. In the allergy the functional activity of N-protein was not altered, whereas its coupling with the catalytic component was impaired by sodium fluoride.