Linked Life Data

3385640

Source:http://linkedlifedata.com/resource/pubmed/id/3385640

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1988-7-29
pubmed:abstractText
The mechanism of smooth muscle relaxing effect of minoxidil sulfate (MxSO4) was investigated in isolated rabbit superior mesenteric artery. MxSO4 (5 X 10(-6) M) was found to effectively relax maximal norepinephrine (NE; at 5 X 10(-6) M) contraction, but failed to relax 80 mM K+-induced contraction. MxSO4-induced relaxation was endothelium independent. When the tissues were exposed to increased extracellular K+ (10-25 mM), and then contracted with NE, the relaxation response to MxSO4 was significantly attenuated. Tetraethylammonium (5-10 mM) pretreatment caused pronounced inhibition of MxSO4-induced relaxation. Pretreatment with ouabain (0.5-5 microM) also significantly inhibited MxSO4 relaxation. This effect of ouabain was found to be due to its effect on K+ gradient. These data suggested a role of K+ permeability during MxSO4 relaxation which was further confirmed when it was found that MxSO4 can cause a significant stimulation of 42K efflux from the mesenteric artery preloaded with 42K. It is suggested that MxSO4 may act as a K+ channel agonist to affect the plasmalemmal Ca++ permeability during agonist activation. Consistent with this, MxSO4 was demonstrated to cause an inhibition of NE-stimulated 45Ca influx in this tissue. Such a strong dependence on K+ permeability makes MxSO4 a unique vasodilator among the clinically used vasodilators.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0022-3565
pubmed:author
pubmed:issnType
Print
pubmed:volume
245
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
751-60
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Mechanism of action of minoxidil sulfate-induced vasodilation: a role for increased K+ permeability.
pubmed:affiliation
Cardiovascular Diseases Research, Upjohn Company, Kalamazoo, Michigan.
pubmed:publicationType
Journal Article, In Vitro