Linked Life Data

1697633

Source:http://linkedlifedata.com/resource/pubmed/id/1697633

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1990-10-9
pubmed:abstractText
The effects of two dihydropyridine calcium channel antagonists (nitrendipine and nifedipine) and two agonists (Bay K8644 and CGP-28392) were tested on high K(+)-induced contractures of frog's toe muscles. All four drugs depressed or blocked maximum contractures induced by 123 mM K+. Agonist effects, i.e., an increase in contracture amplitude, were found with smaller contractures produced by lower high K+ concentrations (i.e., 10, 20, and 25 mM). Bay K8644 produced its maximum agonist effect at 10(-7) M and only depressed contractures with 10(-6) M. CGP-28392 had its greatest agonist effect with 10(-9) M and had only antagonist effects with 10(-7) M or more. Nitrendipine had no agonist effects but nifedipine produced agonist effects with all concentrations tested (10(-9) to 10(-4) M). These results support previous results indicating that these contractures are initiated by extracellular Ca2+ ions entering via the voltage-sensitive, slow calcium channels in the t-tubules. The results obtained in the present study also are consistent with the known pharmacological effects of these drugs on calcium channels.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
0021-521X
pubmed:author
pubmed:issnType
Print
pubmed:volume
40
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
205-24
pubmed:dateRevised
2007-3-21
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Dihydropyridine calcium channel antagonists block and agonists potentiate high potassium contractures but not twitches in frog skeletal muscle.
pubmed:affiliation
Department of Pharmacology, University of Alberta, Edmonton, Canada.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't