Regulation of intracellular cyclic GMP and cyclic AMP levels in mouse lung fragments by disodium cromoglycate, beta-adrenergic agonists, cholinergic activators, and histamine.

The effects of adrenergic and cholinergic agents as well as the effects of disodium cromoglycate (DSCG) on the levels of cyclic AMP and cyclic GMP in mouse lung fragments were studied. Levels of cyclic AMP were enhanced by two of the known beta-adrenergic agonists, epinephrine and isoproterenol. This increase was abolished by propanolol, a recognized beta-adrenergic antagonist. Disodium cromoglycate, a proposed inhibitor of phosphodiesterases, alone caused a slight, significant increase in cyclic AMP. However, in the presence of epinephrine, levels of cyclic AMP were potentiated by DSCG. DSCG behaves, therefore, as a typical cyclic AMP phosphodiesterase inhibitor. Cyclic GMP levels were increased by carbachol, acetylcholine, and the phosphodiesterase inhibitor, aminophylline, but not by DSCG, or beta-adrenergic agonists.