[Changes in the cyclic nucleotide levels during the contraction of smooth muscles exposed to muscarinic cholinomimetics].

Intracellular levels of cyclic nucleotides AMP and GMP were measured in isolated preparations of the guinea pig ileum, taenia coli, bladder and vas deferens. The cAMP level was about ten-fold as high as the cGMP level. During cholinergic stimulation for 5-10 sec contractile response preceded the cGMP rise. Muscarinic cholinomimetics obviously increased the cGMP levels especially in vas deferens, whereas no significant changes occurred in the cAMP levels. Changes in the cGMP levels were only found during phasic tension of muscles.