Characterization of muscarinic receptor subtypes in human tissues
The affinities of selective, pirenzepine and AF-DX 116, and classical, N-methylscopolamine and atropine, muscarinic cholinergic receptor antagonists were investigated in displacement binding experiments with (/sup 3/H)Pirenzepine and (/sup 3/H)N-methylscopolamine in membranes from human autoptic tissues (forebrain, cerebellum, atria, ventricle and submaxillary salivary glands). Affinity estimates of N-methylscopolamine and atropine indicated a non-selective profile. Pirenzepine showed differentiation between the M/sub 1/ neuronal receptor of the forebrain and the receptors in other tissues while AF-DX 116 clearly discriminated between muscarinic receptors of heart and glands. The results in human tissues confirm the previously described selectivity profiles of pirenzepine and AF-DX 116 in rat tissues. These findings thus reveal the presence also in man of three distinct muscarinic receptor subtypes: the neuronal M/sub 1/, the cardiac M/sub 2/ and the glandular M/sub 3/.
- Research Organization:
- Istituto de Angeli S.p.A., Milan (Italy)
- OSTI ID:
- 7055693
- Journal Information:
- Life Sci.; (United States), Journal Name: Life Sci.; (United States) Vol. 43:19; ISSN LIFSA
- Country of Publication:
- United States
- Language:
- English
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59 BASIC BIOLOGICAL SCIENCES
AFFINITY
ALCOHOLS
AMINES
AMMONIUM COMPOUNDS
ANIMALS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CELL CONSTITUENTS
CELL MEMBRANES
CENTRAL NERVOUS SYSTEM
CHOLINE
DRUGS
GLANDS
HYDROXY COMPOUNDS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIPOTROPIC FACTORS
MAMMALS
MAN
MEMBRANE PROTEINS
MEMBRANES
NERVES
NERVOUS SYSTEM
ORGANIC COMPOUNDS
ORGANS
PARASYMPATHOLYTICS
PRIMATES
PROTEINS
QUATERNARY COMPOUNDS
REACTION KINETICS
RECEPTORS
SALIVARY GLANDS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES