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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
3
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pubmed:dateCreated |
1990-12-5
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pubmed:abstractText |
The pressor actions of sarafotoxin-b (SRTX-b) were examined in pithed rats in the presence of the calcium channel antagonist nifedipine or the calcium channel activator BAY K 8644 intraarterially (i.a.) and also after pretreatment with pertussis toxin intravenously (i.v.). SRTX-b produced dose-dependent pressor effects in the pithed rat. The diastolic blood pressure (DBP) recorded in animals treated with the vehicle was 41 +/- 1 mm Hg; administration of BAY K 8644 0.1 or 0.3 mg/kg increased DBP pressure to 50 +/- 1 and 52 +/- 1 mm Hg, respectively, whereas nifedipine 0.1 or 0.3 mg/kg decreased DBP to 39 +/- 1 and 33 +/- 1 mm Hg, respectively. The actions of SRTX-b were significantly inhibited by nifedipine, whereas BAY K 8644 potentiated the pressor actions of SRTX-b. We observed that animals pretreated with pertussis toxin 25 or 50 micrograms/kg 3 days before we conducted the experiments had significantly lower DBP as compared with saline-treated animals. Treatment with pertussis toxin caused the DBP dose-response curve to SRTX-b to be displaced to the right. These results indicate that a nifedipine-sensitive (presumably extracellular) calcium pool is partly responsible for the pressor response induced by SRTX-b. They further suggest that in vascular smooth muscle, at least in some vascular beds, SRTX-b activates a pertussin toxin-sensitive G-protein that is coupled to a receptor-operated calcium or nonspecific cation channel.
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pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/3-Pyridinecarboxylic acid...,
http://linkedlifedata.com/resource/pubmed/chemical/Nifedipine,
http://linkedlifedata.com/resource/pubmed/chemical/Pertussis Toxin,
http://linkedlifedata.com/resource/pubmed/chemical/Vasoconstrictor Agents,
http://linkedlifedata.com/resource/pubmed/chemical/Viper Venoms,
http://linkedlifedata.com/resource/pubmed/chemical/Virulence Factors, Bordetella,
http://linkedlifedata.com/resource/pubmed/chemical/sarafotoxins s6
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pubmed:status |
MEDLINE
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pubmed:month |
Sep
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pubmed:issn |
0160-2446
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
16
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
495-500
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pubmed:dateRevised |
2006-11-15
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pubmed:meshHeading |
pubmed-meshheading:1700223-3-Pyridinecarboxylic acid...,
pubmed-meshheading:1700223-Analysis of Variance,
pubmed-meshheading:1700223-Animals,
pubmed-meshheading:1700223-Blood Pressure,
pubmed-meshheading:1700223-Decerebrate State,
pubmed-meshheading:1700223-Dose-Response Relationship, Drug,
pubmed-meshheading:1700223-Male,
pubmed-meshheading:1700223-Nifedipine,
pubmed-meshheading:1700223-Pertussis Toxin,
pubmed-meshheading:1700223-Rats,
pubmed-meshheading:1700223-Rats, Inbred Strains,
pubmed-meshheading:1700223-Vasoconstrictor Agents,
pubmed-meshheading:1700223-Viper Venoms,
pubmed-meshheading:1700223-Virulence Factors, Bordetella
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pubmed:year |
1990
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pubmed:articleTitle |
Effects of nifedipine, BAY K 8644, and pertussis toxin on pressor response to sarafotoxin-b in pithed rats.
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pubmed:affiliation |
Division of Basic Medical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.
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pubmed:publicationType |
Journal Article,
Comparative Study,
Research Support, Non-U.S. Gov't
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