Linked Life Data

2123615

Source:http://linkedlifedata.com/resource/pubmed/id/2123615

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 1
pubmed:dateCreated
1991-1-17
pubmed:abstractText
Potassium (K+) channels are present on airway smooth muscle cells, and their activation results in hyperpolarization and relaxation. Because these effects may have therapeutic relevance to asthma, we examined the activity of the active L-enantiomer of cromakalim, BRL 38227 (lemakalim), a selective K+ channel activator, against a variety of spasmogens in human bronchi in vitro. BRL 38227 produced relaxation of bronchi with either resting tone or tone induced by histamine, carbachol, neurokinin A, or KCl (20 mM) with an efficacy (%Emax) of 60 to 80% of that of isoproterenol and an EC50 (the concentration producing 50% of the maximal response) of 0.2 to 0.6 microM. However, BRL 38227 had a significantly lower potency and efficacy against 80 mM KCl than against the other spasmogens (%Emax, 12% of isoproterenol and EC50, 7.2 microM; p less than 0.005 and p less than 0.001, respectively), supporting the view that BRL 38227 acts on K+ channels. The D-enantiomer BRL 38226 was less potent (EC50, 2.6 microM) than BRL 38227 and produced only 43% of the isoproterenol relaxation. BRL 38227-induced relaxation was significantly inhibited by the ATP-sensitive K+ channel antagonist glibenclamide (0.1 and 1 microM), with a three-fold and eight-fold shift to the right of the dose-response curve, respectively. In the presence of a maximal relaxation induced by the calcium voltage-dependent channel antagonist verapamil, BRL 38227 was able to produce an additional 37% relaxation response. Thus, BRL 38227 is an effective relaxant of human airway smooth muscle, and this activity results from an action at K+ channels.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0003-0805
pubmed:author
pubmed:issnType
Print
pubmed:volume
142
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1384-9
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
The action of a potassium channel activator, BRL 38227 (lemakalim), on human airway smooth muscle.
pubmed:affiliation
Department of Pharmacology, University of Sydney, Australia.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't