[Relation of the cyclic nucleotide system with the functional state of the cholinoreceptors].

It has been demonstrated in rat experiments that the concentration of cAMP and cGMP in the rat liver increased 15-90 min after administration of the cholinomimetic carbamylcholine (Cr) or the cholinolytic chlorosyl (Ch) at doses of 1 and 2 mg/kg, respectively. Administration of Ch 5 min before Cr blocked the signs of parasympathetic nervous system excitation and made the content of cGMP return to normal. The concentration of cAMP in the liver of these rats as was the case in administration of Ch alone was greatly enhanced, reaching 400% of the control after 60 min. Transcriptional activity of hepatocytes following separate or combined administration of Ch and Cr was increased in 6 hours. Preliminary administration of Ch at a dose of 0.025 mg/kg prevented the excitation of the parasympathetic nervous system and stimulation of hepatocyte transcriptional activity, bringing about a dramatic fall in the liver cAMP and cGMP content. The existence of the relationship between cholinoreceptor function and the pool of cyclic nucleotides in the target cells is postulated.