Characterization of muscarinic cholinergic receptor subtypes in human peripheral lung
The authors have characterized the muscarinic cholinergic receptor subtypes in human peripheral lung membranes using the selective muscarinic antagonist (/sup 3/H)pirenzepine ((/sup 3/H)PZ) and the classical muscarinic antagonist (/sup 3/H)(-)-quinuclidinyl benzilate. High-affinity binding with pharmacologic specificity was demonstrated for both radioligands. The high affinity Kd for (/sup 3/H)PZ binding determined from saturation isotherms was 5.6 nM, and the Kd for (/sup 3/H)(-)-quinuclidinyl benzilate binding was 14.3 pM. Approximately 62% of the total muscarinic binding sites in human peripheral lung bind (/sup 3/H)PZ with high affinity. There was no significant effect of the guanine nucleotide, guanyl-5'-yl imidodiphosphate, on the inhibition of (/sup 3/H)(-)-quinyclidinyl benzilate binding by the muscarinic agonist carbachol in peripheral lung membranes. If the muscarinic receptor with high affinity for PZ has an important role in bronchoconstriction, its characterization could result in the development of more selective bronchodilators.
- Research Organization:
- Univ. of Arizona College of Medicine, Tucson (USA)
- OSTI ID:
- 5210338
- Journal Information:
- J. Pharmacol. Exp. Ther.; (United States), Journal Name: J. Pharmacol. Exp. Ther.; (United States) Vol. 244:2; ISSN JPETA
- Country of Publication:
- United States
- Language:
- English
Similar Records
Muscarinic cholinergic receptor binding sites differentiated by their affinity for pirenzepine do not interconvert
Identification of three muscarinic receptor subtypes in rat lung using binding studies with selective antagonists
Related Subjects
59 BASIC BIOLOGICAL SCIENCES
ACETYLCHOLINE
AFFINITY
AMINES
AMMONIUM COMPOUNDS
AUTONOMIC NERVOUS SYSTEM AGENTS
BIOCHEMICAL REACTION KINETICS
CHEMICAL COMPOSITION
DRUGS
ESTERS
ISOTOPE APPLICATIONS
KINETICS
LABELLED COMPOUNDS
LIGANDS
MEMBRANE PROTEINS
NEUROREGULATORS
ORGANIC COMPOUNDS
PARASYMPATHOLYTICS
PARASYMPATHOMIMETICS
PROTEINS
QUATERNARY COMPOUNDS
REACTION KINETICS
RECEPTORS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VASOCONSTRICTION