Linked Life Data

17805515

Source:http://linkedlifedata.com/resource/pubmed/id/17805515

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1-2
pubmed:dateCreated
2007-11-26
pubmed:abstractText
The acetylcholinesterase knockout mouse has elevated acetylcholine levels due to the complete absence of acetylcholinesterase. Our goal was to determine the adaptive changes in lung receptors that allow these animals to tolerate excess neurotransmitter. The hypothesis was tested that not only muscarinic receptors but also alpha(1)-adrenoceptors and beta-adrenoceptors are downregulated, thus maintaining a proper balance of receptors and accounting for lung function in these animals. The quantity of alpha(1A), alpha(1B), alpha(1D), beta(1), and beta(2)-adrenoceptors and muscarinic receptors was determined by binding of radioligands. G-protein coupling was assessed using pseudo-competition with agonists. Phospholipase C activity was measured by an enzymatic assay. Cyclic AMP (cAMP) content was measured by immunoassay. Muscarinic receptors were decreased to 50%, alpha(1)-adrenoceptors to 23%, and beta-adrenoceptors to about 50% of control. Changes were subtype specific, as alpha(1A), alpha(1B), and beta(2)-adrenoceptors, but not alpha(1D)-adrenoceptor, were decreased. In contrast, receptor signaling into the cell as measured by coupling to G proteins, cAMP content, and PI-phospholipase C activity was the same as in control. This shows that the nearly normal lung function of these animals was explained by maintenance of a correct balance of adrenoceptors and muscarinic receptors. In conclusion, knockout mice have adapted to high concentrations of acetylcholine by downregulating receptors that bind acetylcholine, as well as by downregulating receptors that oppose the action of muscarinic receptors. Tolerance to excess acetylcholine is achieved by reducing the levels of muscarinic receptors and adrenoceptors.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0028-1298
pubmed:author
pubmed:issnType
Print
pubmed:volume
376
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
83-92
pubmed:meshHeading
pubmed:year
2007
pubmed:articleTitle
Adaptation to excess acetylcholine by downregulation of adrenoceptors and muscarinic receptors in lungs of acetylcholinesterase knockout mice.
pubmed:affiliation
Institute of Physiology, 1st Faculty of Medicine, Charles University, Albertov 5, 12800 Prague, Czech Republic. jmys@lf1.cuni.cz
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't, Research Support, N.I.H., Extramural