Linked Life Data

15215632

Source:http://linkedlifedata.com/resource/pubmed/id/15215632

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
2004-6-24
pubmed:abstractText
The possible functional coupling between beta1-adrenoceptor and MaxiK channels which results in smooth muscle relaxation was examined in the guinea-pig esophageal muscularis mucosae. Isoprenaline-elicited relaxation of esophageal smooth muscle was confirmed to be mediated through beta1-adrenoceptors as the response was competitively antagonized by a beta1-selective antagonist atenolol with a pA2 value of 7.01. Iberiotoxin (IbTx, 10(-7) M), a selective MaxiK channel inhibitor, substantially diminished the relaxant response to isoprenaline. The extent of the MaxiK channel contribution to the relaxant response was 15-40% of the control response when estimated as the E50%-Emax responses to isoprenaline. The relaxation to isoprenaline was also attenuated by high-KCl (80 mM) to the same degree as the relaxant response generated in the presence of IbTx, and thus the estimated extent of the K+ channel contribution was 10-40%. These findings indicate that beta1-adrenoceptors are substantially coupled with MaxiK channels to produce relaxation of esophageal smooth muscle in the guinea-pig. Although MaxiK channels account for the contribution of K+ channels to the beta1-adrenoceptor-mediated relaxation in this smooth muscle preparation, their contribution seems to be less when compared to the beta2-adrenoceptor-mediated relaxation of tracheal smooth muscle.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Apr
pubmed:issn
0916-8737
pubmed:author
pubmed:issnType
Print
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
43-52
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
2004
pubmed:articleTitle
Beta1-adrenoceptor-mediated relaxation with isoprenaline and the role of MaxiK channels in guinea-pig esophageal smooth muscle.
pubmed:affiliation
Department of Chemical Pharmacology, Toho University School of Pharmaceutical Sciences, Funabashi-City, Chiba, Japan. yotanaka@phar.toho-u.ac.jp
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't