Linked Life Data

1592474

Source:http://linkedlifedata.com/resource/pubmed/id/1592474

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 2
pubmed:dateCreated
1992-6-30
pubmed:abstractText
Pressurization of isolated arteries may result in Ca(2+)-dependent contraction and membrane depolarization. Because the open state probability of some vascular muscle K+ channels is augmented by rises in cytosolic Ca2+ and membrane depolarization, we investigated the possibility that increases in intraluminal pressure activate K+ channels in isolated, perfused rat saphenous arteries. Stepwise increases in intraluminal pressure from 5 to 205 mm Hg resulted in increasing, active arterial contraction, measured as smaller diameters in physiological salt solution than in Ca(2+)-free solution. Addition of 10 mM tetraethylammonium to the physiological salt solution to block arterial muscle K+ channels caused progressively greater diameter reductions at pressures above 25 mm Hg. Microelectrode measurements of membrane potential showed that tetraethylammonium depolarized arterial muscle more at 105 mm Hg (16 +/- 1 mV) than at 25 mm Hg (10 +/- 1 mV). The sensitivity of K+ current to tetraethylammonium was also demonstrated in patch-clamped vascular muscle cells from the same arteries. Peak whole-cell K+ current was suppressed 47% and 79% by 1 and 10 mM tetraethylammonium, respectively. This same current was enhanced 3.6-fold by the Ca2+ ionophore A23187 (10 microM), suggesting a Ca2+ dependence. We conclude that increases in intraluminal pressure progressively activate tetraethylammonium-sensitive K+ channels in the arterial muscle membrane. This can serve as a negative feedback mechanism to limit pressure-induced arterial constriction.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0194-911X
pubmed:author
pubmed:issnType
Print
pubmed:volume
19
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
725-9
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Pressure-induced activation of membrane K+ current in rat saphenous artery.
pubmed:affiliation
Department of Physiology, Medical College of Wisconsin, Milwaukee 53226.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, U.S. Gov't, Non-P.H.S.