Quantitative autoradiography of brain binding sites for the vesicular acetylcholine transport blocker 2-(4-phenylpiperidino)cyclohexanol (AH5183)

Journal Article · Sun Feb 01 04:00:00 EST 1987 · Proc. Natl. Acad. Sci. U.S.A.; (United States)

DOI:https://doi.org/10.1073/pnas.84.3.876· OSTI ID:6647369

Marien, M R; Parsons, S M; Altar, C A

2-(4-Phenylpiperidino)cyclohexanol (AH5183) is a noncompetitive and potent inhibitor of high-affinity acetylcholine transport into cholinergic vesicles. It is reported here that (/sup 3/H)AH5183 binds specifically and saturably to slide-mounted sections of the rat forebrain (Kd = 1.1 to 2.2 X 10(-8) M; Bmax = 286 to 399 fmol/mg of protein). The association and dissociation rate constants for (/sup 3/H)AH5183 binding are 8.6 X 10(6) M-1 X min-1 and 0.18 min-1, respectively. Bound (/sup 3/H)AH5183 can be displaced by nonradioactive AH5183 and by the structural analog (2 alpha,3 beta,4A beta,8A alpha)-decahydro-3-(4-phenyl-1-piperidinyl)-2- naphthalenol but not by 10 microM concentrations of the cholinergic drugs acetylcholine, choline, atropine, hexamethonium, eserine, or hemicholinium-3 or by the structurally related compounds 1-methyl-4-phenyl-1,2,3,6-tetrahydropyridine, 1-methyl-4-phenylpyridine, (+/-)-N-allylnormetazocine (SKF 10,047), levoxadrol, or dexoxadrol. Quantitative autoradiography reveals that (/sup 3/H)AH5183 binding sites are distributed heterogenously throughout the rat forebrain and are highly localized to cholinergic nerve terminal regions. At the level of the caudate nucleus-putamen, the highest concentrations of saturable (/sup 3/H)AH5183 binding (713-751 fmol/mg of protein) are found in the vertical limb of the diagonal band and the olfactory tubercle, with lesser amounts (334-516 fmol/mg of protein) in the caudate-putamen, nucleus accumbens, superficial layers of the cerebral cortex, and the primary olfactory cortex. At day 7 after transsection of the left fimbria, (/sup 3/H)AH5183 binding and choline acetyltransferase activity in the left hippocampus were reduced by 33 +/- 6% and 61 +/- 7%, respectively. These findings indicate that (/sup 3/H)AH5183 binds to a unique recognition site in rat brain that is topographically associated with cholinergic nerve terminals.

• Research Organization: CIBA-Geigy Corp., Summit, NJ
• OSTI ID: 6647369
• Journal Information: Proc. Natl. Acad. Sci. U.S.A.; (United States), Journal Name: Proc. Natl. Acad. Sci. U.S.A.; (United States) Vol. 3; ISSN PNASA
• Country of Publication: United States
• Language: English

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551001* -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ACETYLCHOLINE
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
AUTORADIOGRAPHY
BODY
BRAIN
CENTRAL NERVOUS SYSTEM
DRUGS
ESTERS
HEXANOLS
HYDROXY COMPOUNDS
INHIBITION
ISOTOPE APPLICATIONS
LABELLED COMPOUNDS
MAMMALS
MEMBRANE PROTEINS
NERVOUS SYSTEM
NEUROREGULATORS
ORGANIC COMPOUNDS
ORGANS
PARASYMPATHOMIMETICS
PROTEINS
QUATERNARY COMPOUNDS
RADIORECEPTOR ASSAY
RATS
RECEPTORS
RODENTS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES