text: In this study the neuromuscular blocking drug vecuronium and the controls gallamine and << pancuronium >> slowed the rate of atropine induced [(3)H]N-methylscopolamine dissociation from Chinese hamster ovary cells expressing recombinant [[ human muscarinic M2 receptors ]] K(off) values min(-1); vecuronium (125 nM), atropine 0.45+/-0.07+blocker 0.04+/-0.02; gallamine (21 nM), atropine 0.42+/-0.05+blocker 0.15+/-0.04; pancuronium(21 nM), atropine 0.36+/-0.03+blocker 0.03+/-0.01).