G protein antagonist

A G protein antagonist which selectively inhibits the activation of Gq by M1 muscarinic cholinergic receptors (mAChR). Not effective in inhibiting M2 mAChR-promoted GTP hydrolysis by Gi. Inhibition is reversible and competitive with respect to receptor binding to G proteins. Also inhibits activation by cholecystokinin receptor in pancreatic acini at 10 µM.