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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5
pubmed:dateCreated
2001-6-8
pubmed:abstractText
The mechanisms of the inhibitory effects of verapamil and nitroglycerin on vasospasm were investigated by measuring cytosolic Ca2+ level ([Ca2+]i) and muscle tension in 28 normal specimens and 28 spastic vascular specimens of smooth muscle. Experimental vasospasm was produced by the two-hemorrhage method in the canine basilar artery. [Ca2+]i and tension were recorded simultaneously with a fluorimeter using fura-2. High K+ concentration (72.4 mM) and U-46619 (thromboxane A2 analogue, 10(-8) M) were used as stimulants, and the inhibitory effects of verapamil or nitroglycerin on muscle contraction and increased [Ca2+]i were examined. Verapamil inhibited [Ca2+]i and contraction in high K+ concentration-stimulated arteries. Verapamil inhibited [Ca2+]i more strongly than contraction in U-46619-stimulated arteries. There were no significant differences in the effects of verapamil in the control and vasospasm groups. Nitroglycerin inhibited contraction with little effect on [Ca2+]i in high K+ concentration-stimulated arteries in both the control and vasospasm groups. Nitroglycerin inhibited contraction with little effect on [Ca2+]i in U-46619-stimulated arteries and the inhibitory effect was weaker in the vasospasm group than in the control group. The inhibitory effects of verapamil on muscle tension and [Ca2+]i in vasospastic vessels were as strong as those in normal vessels. In contrast, the inhibitory effects of nitroglycerin were reduced in vasospastic vessels. Increased Ca2+ sensitivity in vasospastic vessels may have reduced the inhibitory effects of nitroglycerin.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0470-8105
pubmed:author
pubmed:issnType
Print
pubmed:volume
41
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
238-44; discussion 244-5
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:year
2001
pubmed:articleTitle
Inhibitory effects of verapamil and nitroglycerin on contraction and cytosolic Ca2+ levels in cerebrovascular smooth muscle during chronic cerebral vasospasm.
pubmed:affiliation
Department of Surgical Neurology, Jichi Medical School, Tochigi.
pubmed:publicationType
Journal Article