Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
2001-11-27
pubmed:abstractText
The epithelial or endothelial cells that line the human bronchi and the aorta express nicotinic acetylcholine receptors (nAChRs) of alpha3 subtypes. We report here that human bronchial epithelial cells (BEC) and aortic endothelial cells (AEC) express also the nAChR alpha7 subunit, which forms functional nAChRs. Polymerase chain reaction and in situ hybridization experiments detected alpha7 subunit mRNA in cultured human BEC and AEC and in sections of rat trachea. The binding of radiolabeled alpha-bungarotoxin revealed a few thousand binding sites per cell in cultured human BEC and human and bovine AEC. Western blot and immunohistochemistry experiments demonstrated that cultured BEC and AEC express a protein(s) recognized by anti-alpha7 antibodies. Whole-cell patch-clamp studies of cultured human BEC demonstrated the presence of fast-desensitizing currents activated by choline and nicotine that were blocked reversibly by methyllycaconitine (1 nM) and irreversibly by alpha-bungarotoxin (100 nM), consistent with the expression of functional alpha7 nAChRs. In some cells, choline activated also slowly decaying currents, confirming previous reports that BEC express functional alpha3beta4 nAChRs. Exposure of cultured BEC to nicotine (1 microM) for 3 days up-regulated functional alpha7 and alpha3 nAChRs, as indicated by the increased number of cells responding to acetylcholine and choline, with both fast-desensitizing currents, which were blocked irreversibly by alpha-bungarotoxin, and with slowly desensitizing currents, which are alpha-bungarotoxin-insensitive currents. The presence of alpha7 nAChRs in BEC and AEC suggests that some toxic effects of tobacco smoke could be mediated through these nicotine-sensitive receptors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0026-895X
pubmed:author
pubmed:issnType
Print
pubmed:volume
60
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1201-9
pubmed:dateRevised
2010-6-4
pubmed:meshHeading
pubmed-meshheading:11723227-Animals, pubmed-meshheading:11723227-Antibody Specificity, pubmed-meshheading:11723227-Binding Sites, pubmed-meshheading:11723227-Blotting, Western, pubmed-meshheading:11723227-Bronchi, pubmed-meshheading:11723227-Bungarotoxins, pubmed-meshheading:11723227-Cattle, pubmed-meshheading:11723227-Cloning, Molecular, pubmed-meshheading:11723227-Electrophysiology, pubmed-meshheading:11723227-Endothelium, Vascular, pubmed-meshheading:11723227-Epithelial Cells, pubmed-meshheading:11723227-Fluorescent Antibody Technique, pubmed-meshheading:11723227-Humans, pubmed-meshheading:11723227-In Situ Hybridization, pubmed-meshheading:11723227-Iodine Radioisotopes, pubmed-meshheading:11723227-Patch-Clamp Techniques, pubmed-meshheading:11723227-Polymerase Chain Reaction, pubmed-meshheading:11723227-RNA, Messenger, pubmed-meshheading:11723227-Rats, pubmed-meshheading:11723227-Receptors, Nicotinic, pubmed-meshheading:11723227-Trachea, pubmed-meshheading:11723227-Transcription, Genetic
pubmed:year
2001
pubmed:articleTitle
Human bronchial epithelial and endothelial cells express alpha7 nicotinic acetylcholine receptors.
pubmed:affiliation
Department of Pharmacology, University of Minnesota, Minneapolis, Minnesota, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't