Oxotremorine M is a non-selective muscarinic (M) acetylcholine receptor agonist that induces phosphoinositide hydrolysis in mouse ileum isolated from wild-type, M2, M3, and M2/M3 knockout mice (EC50s = 0.36, 0.52, 1.62, and 1.48 μM, respectively). It also increases M4-induced inhibition of calcium currents in NG108-15 mouse neuroblastoma X rat glioma hybrid cells (EC50 = 0.14 μM). Oxotremorine M inhibits KCNQ2/3 potassium currents in Xenopus oocytes expressing M1 receptors and KCNQ2/3 potassium channels (IC50 = 1.1 μM). It also directly inhibits KCNQ2/3 potassium channels, decreasing KCNQ2/3 potassium currents in Xenopus oocytes lacking muscarinic receptors in a dose-dependent manner.
