TD-4208

An antagonist of muscarinic acetylcholine receptors (Kis = 0.42, 0.3, 0.18, and 0.55 nM for M1, M2, M3, and M4 receptors, respectively, in CHO-K1 cell membranes with the human receptors); selective for these receptors over M5 muscarinic receptors (Ki = 6.31 nM in CHO-K1 cell membranes with the human receptor); inhibits AChE-induced calcium mobilization in CHO-K1 cells expressing M2 and M3 muscarinic receptors; decreases AChE-induced contractions in isolated rat trachea in a concentration-dependent manner; decreases AChE-induced bronchoconstriction and reduces pilocarpine-induced salivation, a surrogate test for noisy breathing, in rats (ID50s = 45 and 1,164 µg/ml, respectively); decreases AChE-induced bronchoconstriction in dogs at 10 and 30 µg/kg intranasally