Linked Life Data

3444482

Source:http://linkedlifedata.com/resource/pubmed/id/3444482

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6
pubmed:dateCreated
1988-5-3
pubmed:abstractText
The effects of the calcium entry blockers verapamil (V), diltiazem (D), nifedipine (NF) and nicardipine (NC) have been studied on calcium concentration-effect curves elicited in depolarized (K+, 40 mmol/l) and in serotonin-exposed (6 mumol/l) rat middle cerebral arteries (RMCA) in order to compare the relative potencies of the blockers against these two calcium channel activating mechanisms. In control conditions, Ca2+ sensitivity expressed as pD2 and maximal active wall tension (AWT) were not significantly different in depolarized and in 5-HT-exposed vessels: pD2: 3.39 +/- 0.08 vs 3.50 +/- 0.06 and AWT: 0.93 +/- 0.15 mN.mm-1 vs 0.90 +/- 0.16 mN.mm-1 respectively. V, D, NF and NC displaced Ca2+ control curves to the right and depressed the maximum contractile response in the two experimental conditions, which suggests a noncompetitive type of antagonism. All the blockers were more potent inhibitors of Ca2+-induced contractions in depolarized than in serotonin-exposed middle cerebral arteries. The IC50 values (concentration of blockers producing a 50% inhibition of maximal control contractile response) were (nmol/l): V = 20, D = 120, NF = 0.4, NC = 1 and V = 400, D = 10,000, NF = 20, NC = 7 in depolarized and serotonin-exposed arteries respectively. From these IC50 values, the relative order of potency of the CEB's was not the same in the two experimental conditions suggesting that while serotonin and K+ both promote the entry of Ca2+ into vascular smooth muscle cells of RMCA, they either activate a different gating mechanism associated with a single common channel or perhaps distinct channels.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Dec
pubmed:issn
0028-1298
pubmed:author
pubmed:issnType
Print
pubmed:volume
336
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
670-6
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1987
pubmed:articleTitle
Compared effects of calcium entry blockers on calcium-induced tension in rat isolated cerebral and peripheral resistance vessels.
pubmed:affiliation
Université Louis Pasteur, Laboratoire de Pharmacodynamie (CNRS UA 600), Strasbourg, France.
pubmed:publicationType
Journal Article, Comparative Study, In Vitro, Research Support, Non-U.S. Gov't