Switch to
Predicate | Object |
---|---|
rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
|
pubmed:dateCreated |
1992-1-13
|
pubmed:abstractText |
The possible involvement of a GTP-binding protein in the regulation of Ca2+ channels by angiotensin II (Ang II) in vascular muscle cells was investigated by the whole-cell voltage-clamp method. Single cells were freshly isolated from guinea pig portal vein. The pipette solution contained high Cs+ to inhibit K+ currents and thereby isolate the Ca2+ channel current. Ba2+ (2 mM) was in the bath solution as a charge carrier for the Ca2+ channel. Application of Ang II (0.1-100 nM) produced an increase in peak amplitude of the Ba2+ current, with a shift of the current-voltage curve in the negative direction. These effects were inhibited by pretreatment with an antagonist of the Ang II receptor, [Sar1,Ile8]-Ang II. Presence of 0.1 mM GTP in the pipette solution stabilized the Ang II action, but 0.3-1.0 mM GDP-beta-S and 1.0 mM GTP-gamma-S inhibited it. GTP-gamma-S alone produced a slowly progressing increase in the basal (unstimulated) current amplitude. Preincubation of muscle tissues with pertussis toxin (1 micrograms/ml, for up to 6 hours at 36 degrees C) or intracellular application of preactivated pertussis toxin (1 micrograms/ml) plus NAD (1 mM) did not inhibit the Ang II action. Cholera toxin (10 micrograms/ml) also had no effect on the Ang II action. These results suggest that the Ang II stimulation of Ca2+ channels in smooth muscle of guinea pig portal vein may be mediated by a G protein that is insensitive to both pertussis toxin and cholera toxin.
|
pubmed:grant | |
pubmed:language |
eng
|
pubmed:journal | |
pubmed:citationSubset |
IM
|
pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/Angiotensin II,
http://linkedlifedata.com/resource/pubmed/chemical/Barium,
http://linkedlifedata.com/resource/pubmed/chemical/Calcium Channels,
http://linkedlifedata.com/resource/pubmed/chemical/Cholera Toxin,
http://linkedlifedata.com/resource/pubmed/chemical/GTP-Binding Proteins,
http://linkedlifedata.com/resource/pubmed/chemical/Guanosine 5'-O-(3-Thiotriphosphate),
http://linkedlifedata.com/resource/pubmed/chemical/Pertussis Toxin,
http://linkedlifedata.com/resource/pubmed/chemical/Virulence Factors, Bordetella,
http://linkedlifedata.com/resource/pubmed/chemical/guanosine 5'-O-(2-thiotriphosphate)
|
pubmed:status |
MEDLINE
|
pubmed:month |
Mar
|
pubmed:issn |
0009-7330
|
pubmed:author | |
pubmed:issnType |
Print
|
pubmed:volume |
68
|
pubmed:owner |
NLM
|
pubmed:authorsComplete |
Y
|
pubmed:pagination |
763-71
|
pubmed:dateRevised |
2007-11-14
|
pubmed:meshHeading |
pubmed-meshheading:1660361-Angiotensin II,
pubmed-meshheading:1660361-Animals,
pubmed-meshheading:1660361-Barium,
pubmed-meshheading:1660361-Calcium Channels,
pubmed-meshheading:1660361-Cholera Toxin,
pubmed-meshheading:1660361-GTP-Binding Proteins,
pubmed-meshheading:1660361-Guanosine 5'-O-(3-Thiotriphosphate),
pubmed-meshheading:1660361-Muscle, Smooth, Vascular,
pubmed-meshheading:1660361-Pertussis Toxin,
pubmed-meshheading:1660361-Virulence Factors, Bordetella
|
pubmed:year |
1991
|
pubmed:articleTitle |
Involvement of a GTP-binding protein in stimulating action of angiotensin II on calcium channels in vascular smooth muscle cells.
|
pubmed:affiliation |
Department of Physiology and Biophysics, University of Cincinnati, Ohio 45267-0576.
|
pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
|