Linked Life Data

7525130

Source:http://linkedlifedata.com/resource/pubmed/id/7525130

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
1994-12-8
pubmed:abstractText
1. The role of calcium-activated potassium (KCa) channels in bronchodilation produced by a direct adenylyl cyclase activator, forskolin, was investigated. The involvement of intracellular cyclic AMP (cAMP) in the process was also examined. 2. The isometric tension records from guinea-pig tracheal smooth muscles indicated that application of charybdotoxin (ChTX), a selective inhibitor of large conductance KCa channels, led to a suppression of the relaxant effect of forskolin in the precontracted tissue by carbachol (CCh). However, the inhibitory action by ChTX had a much greater effect on the relaxation caused by isoproterenol than by forskolin. 3. In contrast to the effect of ChTX, glybenclamide, a cromakalim-sensitive K+ channel inhibitor and apamin, a small conductance KCa channel blocker, had no effects on the bronchodilation produced by forskolin. 4. The effects of forskolin and nifedipine on tone produced by high K+ was compared. Concentration-inhibition curves in guinea-pig trachealis precontracted by 20 mmol/L K+ solution were similar for forskolin and nifedipine. Conversely, relaxation by forskolin was significantly diminished when tissues were contracted with 40 mmol/L K+ solution, whereas nifedipine relaxations were unaffected. 5. A single channel record from a cell-attached patch in a porcine tracheal myocyte demonstrated that forskolin stimulates reversibly KCa channels without affecting the unitary amplitude. 6. The results are consistent with forskolin-induced relaxation occurring at least in part through the opening of ChTX-sensitive KCa channels, by means of a cAMP-dependent channel modulation.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0305-1870
pubmed:author
pubmed:issnType
Print
pubmed:volume
21
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
367-75
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1994
pubmed:articleTitle
Role of calcium-activated potassium channels in the relaxation of tracheal smooth muscles by forskolin.
pubmed:affiliation
Second Department of Internal Medicine, School of Medicine, Nagoya University, Japan.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro