Linked Life Data

12391270

Source:http://linkedlifedata.com/resource/pubmed/id/12391270

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2002-10-22
pubmed:abstractText
The heart is richly endowed with K(ATP) channels, which function as biological sensors, regulating membrane potentials and electrical excitability in response to metabolic alterations. We recently reported that the cytochrome P450 metabolites of arachidonic acid, epoxyeicosatrienoic acids (EETs), potently activate cardiac K(ATP) channels by reducing channel sensitivity to ATP. In the present study, we further demonstrate that 11(S),12(R)-EET activated the cardiac K(ATP) channels with an EC(50) of 39.5 nM, whereas 11(R),12(S)-EET was totally inactive. In addition, 11(S),12(R)-EET but not 11(R),12(S)-EET hyperpolarized the resting membrane potentials and shortened the duration of cardiomyocyte action potentials. By studying homologs and analogs of 11,12-EET, we also found that all four EET regioisomers are equipotent activators of the K(ATP) channels, reducing the ATP sensitivity by more than 10-fold; however, neither altered chain length, double bond number, epoxide position, nor methylation of the carboxyl group affected channel inhibitions by ATP. All the fatty epoxides studied are potent K(ATP) channel activators, but the omega-3 homolog was particularly potent, reducing ATP sensitivity 27-fold. Together, the results indicate that the presence of an epoxide group in a particular three-dimensional configuration is a critical determinant for K(ATP) channel activation, and its effect is augmented by a double bond at omega-3 position. The results also suggest that fatty epoxides are important modulators of cardiac electrical excitability.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0026-895X
pubmed:author
pubmed:issnType
Print
pubmed:volume
62
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1076-83
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
2002
pubmed:articleTitle
Stereospecific activation of cardiac ATP-sensitive K(+) channels by epoxyeicosatrienoic acids: a structural determinant study.
pubmed:affiliation
Department of Internal Medicine, Mayo Clinic, Rochester, Minnesota 55905, USA.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't