Linked Life Data

1851703

Source:http://linkedlifedata.com/resource/pubmed/id/1851703

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1991-6-26
pubmed:abstractText
Previous studies have established that nitrovasodilators potentiate the inhibition of platelet function by activators of adenylyl cyclase, but uncertainty exists as to whether a comparable effect is seen in vascular smooth muscle. We initially studied the effects of the nitrovasodilators, sodium nitroprusside (SNP) and 3-morpholinosydnonimine (SIN-1), on the relaxation by isoprenaline of rat aortic smooth muscle that had been precontracted by phenylephrine. Concentrations of SNP (0.25 nM) and SIN-1 (30 nM) that relaxed aortic smooth muscle less than 30% alone, caused significant (3-fold) decreases in the IC50 values for isoprenaline. The cAMP phosphodiesterase inhibitors, cilostamide (20 nM) and Ro 20-1724 (10 microM), caused comparable reductions in the IC50 values for isoprenaline. At these concentrations, each of the four compounds also increased the maximum relaxation achieved with isoprenaline. Even more marked synergistic interactions were observed between isoprenaline and either the nitrovasodilators or the cAMP phosphodiesterase inhibitors when these compounds were added simultaneously before contraction of aortic smooth muscle by phenylephrine. Thus, concentrations of SNP (5 nM), SIN-1 (1 microM), cilostamide (1 microM) and Ro 20-1724 (100 microM) that inhibited contraction by less than 30% decreased the IC50 values for isoprenaline by 8- to 10-fold. At the above concentrations, these compounds each caused a supra-additive inhibition of contraction when added with 100 nM isoprenaline. Thus, synergism between nitrovasodilators and isoprenaline, an activator of adenylyl cyclase, could be detected in vascular smooth muscle and was particularly marked when inhibition of contraction was studied. This action of nitrovasodilators resembled that of inhibitors of cAMP phosphodiesterase.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0014-2999
pubmed:author
pubmed:issnType
Print
pubmed:day
10
pubmed:volume
192
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
235-42
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Synergistic actions of nitrovasodilators and isoprenaline on rat aortic smooth muscle.
pubmed:affiliation
Department of Pathology, McMaster University, Hamilton, Ontario, Canada.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't