Characterization of nicotine binding in mouse brain and comparison with the binding of alpha-bungarotoxin and quinuclidinyl benzilate

Journal Article · Mon Nov 01 04:00:00 EST 1982 · Mol. Pharmacol.; (United States)

OSTI ID:5999180

Marks, M J; Collins, A C

The binding of (/sup 3/H)nicotine to mouse brain has been measured and subsequently compared with the binding of (/sup 125/I)alpha-bungarotoxin (alpha-BTX) and L-(/sup 3/H)quinuclidinyl benzilate (QNB). The binding of nicotine was saturable, reversible, and stereospecific. The average KD and Bmax were 59 nM and 88 fmoles/mg of protein, respectively. Although the rates of association and dissociation of nicotine were temperature-dependent, the incubation temperature had no effect on either KD or Bmax. When measured at 20 degrees or 37 degrees, nicotine appeared to bind to a single class of binding sites, but a second, very low-affinity, binding site was observed at 4 degrees. Nicotine binding was unaffected by the addition of NaCl, KCl, CaCl/sub 2/, or MgSO/sub 4/ to the incubation medium. Nicotinic cholinergic agonists were potent inhibitors of nicotine binding; however, nicotinic antagonists were poor inhibitors. The regional distribution of binding was not uniform: midbrain and striatum contained the highest number of receptors, whereas cerebellum had the fewest. Differences in site densities, regional distribution, inhibitor potencies, and thermal denaturation indicated that nicotine binding was not the same as either QNB or alpha-BTX binding, and therefore that receptors for nicotine may represent a unique population of cholinergic receptors.

• Research Organization: Institute for Behavioral Genetics and School of Pharmacy, University of Colorado, Boulder
• OSTI ID: 5999180
• Journal Information: Mol. Pharmacol.; (United States), Journal Name: Mol. Pharmacol.; (United States) Vol. 22:3; ISSN MOPMA
• Country of Publication: United States
• Language: English

Related Subjects

550201* -- Biochemistry-- Tracer Techniques
551001 -- Physiological Systems-- Tracer Techniques
59 BASIC BIOLOGICAL SCIENCES
ALKALOIDS
AMINES
ANIMALS
ANTIGENS
AUTONOMIC NERVOUS SYSTEM AGENTS
AZINES
AZOLES
BENZILIC ACID
BETA DECAY RADIOISOTOPES
BIOCHEMICAL REACTION KINETICS
BODY
BRAIN
CARBOXYLIC ACIDS
CENTRAL NERVOUS SYSTEM
CHEMICAL BONDS
DAYS LIVING RADIOISOTOPES
DRUGS
ELECTRON CAPTURE RADIOISOTOPES
HETEROCYCLIC COMPOUNDS
HYDROXY ACIDS
INTERMEDIATE MASS NUCLEI
IODINE 125
IODINE ISOTOPES
ISOTOPE APPLICATIONS
ISOTOPES
KINETICS
LABELLED COMPOUNDS
MAMMALS
MATERIALS
MICE
NERVOUS SYSTEM
NICOTINE
NUCLEI
ODD-EVEN NUCLEI
ORGANIC ACIDS
ORGANIC COMPOUNDS
ORGANIC NITROGEN COMPOUNDS
ORGANS
PARASYMPATHOLYTICS
PARASYMPATHOMIMETICS
PHYSIOLOGY
PYRIDINES
PYRROLES
PYRROLIDINES
RADIOISOTOPES
REACTION KINETICS
RECEPTORS
RODENTS
TOXIC MATERIALS
TOXINS
TRACER TECHNIQUES
TRITIUM COMPOUNDS
VERTEBRATES