Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2005-1-17
pubmed:abstractText
We investigated the ability of the muscarinic antagonist p-fluorohexahydrosiladifenidol to inhibit muscarinic agonist-induced contractions and phosphoinositide hydrolysis in the guinea pig ileum and trachea. This antagonist displayed higher potency at blocking oxotremorine-M-induced contractions of the ileum compared with those of the trachea. When estimated using a simple model for competitive antagonism, the observed dissociation constant of p-fluorohexahydrosiladifenidol exhibited approximately 12-fold higher potency in the ileum compared with the trachea. We also investigated the ability of p-fluorohexahydrosiladifenidol to affect the inhibition of contraction caused by the known competitive muscarinic antagonist atropine. Using resultant analysis to analyze this interaction, we found that the true dissociation constant of p-fluorohexahydrosiladifenidol for competitively antagonizing oxotremorine-M-induced contractions in the ileum exhibited significantly lower potency than when calculated assuming a simple competitive model. In contrast, resultant analysis showed little difference between the true and observed potencies of p-fluorohexahydrosiladifenidol for antagonizing oxotremorine-M-induced contractions in the trachea. Using a simple competitive model, we found little difference in the observed dissociation constant of p-fluorohexahydrosiladifenidol for antagonizing oxotremorine-M-induced phosphoinositide hydrolysis in guinea pig ileum and bovine trachea. We also noted that p-fluorohexahydrosiladifenidol (0.3-1.0 microM) moderately inhibited histamine-induced contractions of ileum but not of trachea. Our results suggest that p-fluorohexahydrosiladifenidol does not discriminate markedly between M(3) muscarinic receptors in the ileum and trachea and that it may posses a more potent, nonmuscarinic inhibitory effect on contraction in the ileum.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Feb
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
312
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
592-600
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2005
pubmed:articleTitle
Comparison of the antimuscarinic action of p-fluorohexahydrosiladifenidol in ileal and tracheal smooth muscle.
pubmed:affiliation
Department of Pharmacology, University of California, Irvine, Irvine, CA 92697-4625, USA. fjehlert@uci.edu
pubmed:publicationType
Journal Article, Comparative Study, In Vitro