Cited by 51Nicotinic Acetylcholine Receptors StudySmoking Behavior and CessationNeuroscience and Neuropharmacology Research

Regulation of nicotinic receptors in rat brain following quasi‐irreversible nicotinic blockade by chlorisondamine and chronic treatment with nicotine

Open access
El‐Bizri, H., Clarke, P.B.S.·1994·British Journal of Pharmacology

Abstract

Chronic administration of nicotinic agonists in vivo increases the density of brain nicotinic binding sites. It has been proposed that this up‐regulation results from agonist‐induced functional blockade of nicotinic receptors. This hypothesis was tested by examining post mortem [3 H]‐nicotine and [125 I]‐α‐bungarotoxin ([125 I]‐αBTX) binding following treatment in vivo with the quasi‐irreversible and insurmountable CNS nicotinic blocker chlorisondamine, given either alone or in combination with chronic nicotine administration. In rats that had not received chlorisondamine pretreatment, chronic nicotine administration (0.6 mg kg−1 s.c, twice daily for 12 days) increased [3 H]‐nicotine binding density (Bmax) in forebrain tissue sections by 19%, with no change in the apparent dissociation constant (KD). Chlorisondamine (10 mg kg−1, s.c), given once prior to the chronic treatment phase, neither increased [3 H]‐nicotine binding by itself, nor altered the extent of nicotine‐induced up‐regulation. Nevertheless, chlorisondamine pretreatment resulted in a persistent blockade of CNS nicotinic receptors, as demonstrated by complete block of acute locomotor responses to nicotine. In a second experiment, [3 H]‐nicotine and [125 I]‐αBTX binding was measured in tissue homogenates prepared from several brain regions. In the absence of chlorisondamine pretreatment, chronic nicotine administration (1 mg kg−1 s.c, twice daily for 12 days) increased the Bmax of [3 H]‐nicotine binding in the cerebral cortex (by 34%), striatum (by 28%), midbrain (by 16%) and hippocampus (by 36%); KD was unchanged. As before, this up‐regulation was neither mimicked nor blocked by chlorisondamine pretreatment (10 mg kg−1, s.c, given twice), despite persistent blockade of acute locomotor responses to nicotine. Chronic nicotine treatment also increased the Bmax (but not KD) of [125 I]‐αBTX binding in cerebral cortex (by 35%), hippocampus (by 46%) and midbrain (by 35%). Chlorisondamine altered neither Bmax nor KD when given alone, but significantly attenuated the nicotine‐induced up‐regulation of toxin binding sites in midbrain, with a similar trend in the other two regions. The finding that chronic receptor blockade neither mimicked nor blocked the agonist‐induced up‐regulation of [3 H]‐nicotine binding sites suggests that up‐regulation of these receptors is not determined by their functional status. In contrast, it appears that chronic nicotine‐induced up‐regulation of [125 I]‐αBTX binding sites may result from receptor activation.

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Integrity signals

Registry

Crossref · 10.1111/j.1476-5381.1994.tb17080.x

Cites

40 of 40 references verified0 citation errors · 0 not checkable

Statistics

Claims the paper makes

The claims and statistics of this paper haven’t been checked yet.

Run the check — free, no account needed. It reads the open-access text and checks the sources it cites.

A few free checks a day · papers already verified open instantly · results are public

Claims other papers make about this one

Each is checked against this paper’s own text: does it say what the citing paper says it does?

Self-check

Percentages, sums and reported differences re-computed from the paper’s own numbers.

The self-check needs the paper’s full text.

Cites

Flagged first, then by citations

Research works printed but not linked: 1

  1. GLANTZ, S.A. (1992). Primer of Biostatistics. 3rd edn. New York: McGraw-Hill.

Cited by

Sorted by citations

Authors
El‐Bizri, H., & Clarke, P. B. S.
Affiliations
McGill University (CA)
Corresponding author
Clarke, P.B.S.
Venue
British Journal of Pharmacology
Publisher
Wiley
Published
1994-11
Volume
113
Issue
3
Pages
917-925
ISSN
  • 0007-1188 (ISSN-L)
  • 1476-5381
OpenAlex
W2027945500
Cited by
51
References
40
Citations by year
2020: 1 · 2015: 2 · 2013: 1 · 2012: 1
FWCI
1.90
Type
journal article
Language
en
Open access
Locations
  • British Journal of Pharmacology (publishedVersion)
  • PubMed Central (publishedVersion)
  • PubMed (publishedVersion)
  • eScholarship@McGill (McGill) (submittedVersion)
Funders
  • Medical Research Council Canada
  • Fonds de Recherche du Québec - Santé
  • Medical Research Council
Topics
  • Life Sciences › Biochemistry, Genetics and Molecular Biology › Molecular Biology › Nicotinic Acetylcholine Receptors Study
  • Health Sciences › Medicine › Physiology › Smoking Behavior and Cessation
  • Life Sciences › Neuroscience › Cellular and Molecular Neuroscience › Neuroscience and Neuropharmacology Research
Keywords
nicotinic acetylcholine receptors, receptor up-regulation, chlorisondamine, nicotine, alpha-bungarotoxin binding, cerebral cortex, hippocampus, striatum, midbrain, forebrain, chronic nicotine administration, rats
MeSH terms
Animals, Binding Sites, Brain Chemistry, Bungarotoxins, Chlorisondamine, Male, Motor Activity, Nicotine, Receptors, Nicotinic, Up-Regulation, Rats, Sprague-Dawley, Rats

About these checks

Registry, retraction, Cites and statistics results are computed, not judged, with one exception: a printed reference that no index lists is read once by a model before it counts as a citation error. Claims are extracted by a model and kept only when their quote appears verbatim in the text; each cited source is then checked, with a model’s help, for whether it says what the claim relies on. Those verdicts can be wrong — read the claim’s quote and the cited source before relying on one.

Statistics and arithmetic are recomputed, not judged.

Confidence bands are shown only for fields calibrated on our annotated test set. None is calibrated yet, so no band is shown.

What counts as a claim ›How we measure confidence ›How we check this ›

Are you an author, or do you see a problem with this page? Request a review