title: Characterization of muscarinic receptors modulating acetylcholine release in the rat neostriatum.
abstract: Two classical and two nonclassical muscarinic agents were tested for their effects on neostriatal acetylcholine (ACh) release. The classical muscarinic antagonist, atropine (0.1-2 microM), increased ACh release in a dose-dependent fashion, whereas the 'nonclassical' antagonist, pirenzepine (2-200 microM), had no effect on ACh release. The muscarinic agonist, oxotremorine (1-100 microM), and its analog, oxotremorine-M (0.1-50 microM), both decreased ACh release in a dose-dependent fashion. The inhibitory potency of oxotremorine-M was approximately 20 times that of oxotremorine, and the inhibitory effects of both agonists were blocked by atropine. The results obtained with the muscarinic antagonists indicate that 'M-2 type' muscarinic receptors mediate ACh release in the neostriatum, but further pharmacological analyses are required to assign with certainty the receptor subtype involved in neostriatal ACh release.
authors.affiliation: University of Wisconsin, School of Pharmacy, Madison 53706.
authors.forename: M H
authors.initials: MH
authors.lastname: Weiler
mesh_terms: D000109:Acetylcholine / Q000378:metabolism*; D000818:Animals; D001285:Atropine / Q000494:pharmacology*; D003342:Corpus Striatum / Q000187:drug effects / Q000502:physiology*; D066298:In Vitro Techniques; D007700:Kinetics; D010095:Oxotremorine / Q000494:pharmacology*; D010890:Pirenzepine / Q000494:pharmacology*; D051381:Rats; D011916:Rats, Inbred F344; D011976:Receptors, Muscarinic / Q000187:drug effects / Q000502:physiology*
chemical_list: D011976:Receptors, Muscarinic; D010890:Pirenzepine; D010095:Oxotremorine; D001285:Atropine; D000109:Acetylcholine