the effects of guanine nucleotides on the binding affinity of muscarinic cholinergic receptors for muscarinic agents were studied in rat anterior pituitary membranes using direct ligand binding methods with [ 3h ] quinuclidinyl benzylate , gtp and gpp ( nh ) p at a concentration of 0.1 mm markedly decreased the binding affinity of the agonist , oxotremorine , for the receptors but had no effect on the binding of the antagonist , atropine .
C0018353
gtp
C0018366
gpp ( nh ) p