Linked Life Data

2316703

Source:http://linkedlifedata.com/resource/pubmed/id/2316703

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3 Pt 2
pubmed:dateCreated
1990-4-23
pubmed:abstractText
Angiotensin II (ANG II) is a powerful vasoconstrictor of coronary vessels and other smooth muscles. One of the actions of ANG II is the inhibition of K+ currents, possibly contributing to depolarization and contraction. Therefore, we investigated the role of ANG II on the regulation of K+ channels at the single-channel level. We studied its effect on calcium-activated potassium (KCa) channels (congruent to 250 pS) from coronary smooth muscle incorporated into lipid bilayers. KCa channels were sensitive to externally applied ANG II at voltages from -20 to -70 mV and pCa between 6.5 and 4. The dose-response curve gave a concentration of half-inhibition (Ki1/2) of 58 nM and a Hill coefficient of 2.2, indicating a minimum of two sites in the process. ANG II modified the open and closed states of the channel, affecting their proportions and their values. In addition, a new much slower (congruent to 1 s) closed or "blocked" state appeared. We conclude that one of the mechanisms by which ANG II causes vasoconstriction of the coronary vessels is a direct inhibition of KCa channels contributing to depolarization and contraction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
258
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
H912-5
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
ANG II inhibits calcium-activated potassium channels from coronary smooth muscle in lipid bilayers.
pubmed:affiliation
Department of Molecular Physiology and Biophysics, Baylor College of Medicine, Houston, Texas 77030.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't