IBMX is a widely-used non-specific inhibitor of cyclic AMP (cAMP) and cyclic GMP (cGMP) phosphodiesterases (PDEs) (IC50 = 19, 50, 18, 13, 32, 7, and 50 μM for PDE1, PDE2, PDE3, PDE4, PDE5, PDE7, and PDE11, respectively). PDE8A, PDE8B, and PDE9 are insensitive to IBMX. By inhibiting PDEs, IBMX increases cellular cAMP and cGMP levels, activating cyclic-nucleotide-regulated protein kinases. Methylxanthines, including IBMX, caffeine, and theophylline, bind adenosine receptors,typically antagonizing the suppressive effects of natural agonists. Non-specific inhibitor of cAMP and cGMP phosphodiesterases. The increase in cAMP level as a result of phosphodiesterase inhibition by IBMX activates PKA leading to decreased proliferation, increased differentiation, and induction of apoptosis. IBMX inhibits phenylephrine-induced release of 5-hydroxytryptamine from neuroendocrine epithelial cells of the airway mucosa (IC50: 1.3 μM). Also serves as an adenosine receptor antagonist. Shown to inhibit ion channels in the neuromuscular junction, GH3 cells, and vascular smooth muscle cells. Induces calcium release from intracellular stores in sensory neurons.
Associated Targets
PDE3BTclin cGMP-inhibited 3',5'-cyclic phosphodiesterase B 1 Activities
