title: Allosteric effects of diprobutine on acetylcholine receptors.
abstract: The nicotinic effects of a novel antiparkinsonian compound, diprobutine were investigated on the acetylcholine receptor (AChR) from Torpedo marmorata electric organ and on rat brain membranes by a variety of techniques including stopped flow measurements. On the nicotinic AChR from Torpedo, diprobutine behaved as a typical noncompetitive blocker: it inhibited the agonist-regulated 22Na+ efflux from excitable microsacs; it shifted in the ms-s time-range the conformation of the AChR towards a high affinity state for agonists; it competed with [3H]PCP bound to its high affinity 'allosteric' site. On rat brain membrane, it displaced [3H]PCP bound to its high affinity site. The pharmacological properties of diprobutine are discussed in the context of its biochemical effects.
mesh_terms: D000495:Allosteric Site / Q000187:drug effects; D000818:Animals; D000978:Antiparkinson Agents / Q000494:pharmacology*; D001667:Binding, Competitive; D001921:Brain / Q000378:metabolism; D002082:Butylamines / Q000494:pharmacology*; D002217:Carbachol / Q000378:metabolism; D004557:Electric Organ / Q000378:metabolism; D006168:Guinea Pigs; D066298:In Vitro Techniques; D007700:Kinetics; D008297:Male; D010539:Permeability; D051381:Rats; D011950:Receptors, Cholinergic / Q000187:drug effects*; D017981:Receptors, Neurotransmitter / Q000378:metabolism; D011978:Receptors, Nicotinic / Q000187:drug effects; D017478:Receptors, Phencyclidine; D012964:Sodium / Q000378:metabolism; D014101:Torpedo
chemical_list: D000978:Antiparkinson Agents; D002082:Butylamines; D011950:Receptors, Cholinergic; D017981:Receptors, Neurotransmitter; D011978:Receptors, Nicotinic; D017478:Receptors, Phencyclidine; C045947:diprobutine; D002217:Carbachol; D012964:Sodium