In vitro activity: Aminophylline causes bronchodilation, diuresis, central nervous system and cardiac stimulation, and gastric acid secretion by blocking phosphodiesterase which increases tissue concentrations of cyclic adenosine monophosphate (cAMP) which in turn promotes catecholamine stimulation of lipolysis, glycogenolysis, and gluconeogenesis, and induces release of epinephrine from adrenal medulla cells.

Kinase Assay: Aminophylline is a competitive nonselective phosphodiesterase inhibitor which raises intracellular cAMP, activates PKA, inhibits TNF-alpha and leukotriene[14] synthesis, and reduces inflammation and innate immunity and nonselective adenosine receptor antagonist.