Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1990-12-5
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.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Sep
pubmed:issn
0160-2446
pubmed:author
pubmed:issnType
Print
pubmed:volume
16
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
495-500
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Effects of nifedipine, BAY K 8644, and pertussis toxin on pressor response to sarafotoxin-b in pithed rats.
pubmed:affiliation
Division of Basic Medical Sciences, Faculty of Medicine, Memorial University of Newfoundland, St. John's, Canada.
pubmed:publicationType
Journal Article, Comparative Study, Research Support, Non-U.S. Gov't