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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
2 Pt 2
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pubmed:dateCreated |
1994-4-26
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pubmed:abstractText |
We examined the effect of small changes in extracellular Na+ concentration ([Na+]e) on myogenic tone (MT) in isometrically mounted ring segments of the rabbit facial vein and in pressurized cannulated posterior cerebral artery segments. Decreasing [Na+]e from 150 to 120 mM in the vein increased MT by 24%, and raising [Na+]e to 165 mM attenuated it by 30%. In pressurized posterior cerebral arteries, decreasing [Na+]e to 120 mM reduced the intraluminal diameter by 12%, whereas increasing [Na+]e to 165 mM increased it by 17%. MT was inhibited by amiloride [50% inhibitory concentration (IC50) = 17 +/- 6 microM], an inhibitor of Na(+)-H+ exchange. Diisothiocyanatostilbene sulfonic acid, a Na(+)-Cl(-)-HCO3- cotransporter blocker, inhibited MT with an IC50 of 4.4 +/- 0.65 microM. Ouabain increased MT [50% effective concentration (EC50) = 0.10 +/- 0.04 microM] as did the reintroduction of HCO3- (EC50 5.0 +/- 1.5 mM). Our study suggests that MT in the rabbit posterior cerebral artery and rabbit facial vein is modulated by changes in [Na+]e. This effect is independent of the method used to register changes in wall force. The sensitivity of the tone to changes in [Na+]e and the independence of vessel diameter at different pressures at various [Na+]e may reflect changes in the sensitivity of smooth muscle stretch or mechanoreceptors to [Na+]e.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
http://linkedlifedata.com/resource/pubmed/chemical/4,4'-Diisothiocyanostilbene-2,2'-Dis...,
http://linkedlifedata.com/resource/pubmed/chemical/Amiloride,
http://linkedlifedata.com/resource/pubmed/chemical/Bicarbonates,
http://linkedlifedata.com/resource/pubmed/chemical/Cimetidine,
http://linkedlifedata.com/resource/pubmed/chemical/Histamine,
http://linkedlifedata.com/resource/pubmed/chemical/Meglumine,
http://linkedlifedata.com/resource/pubmed/chemical/Monensin,
http://linkedlifedata.com/resource/pubmed/chemical/Nifedipine,
http://linkedlifedata.com/resource/pubmed/chemical/Norepinephrine,
http://linkedlifedata.com/resource/pubmed/chemical/Ouabain,
http://linkedlifedata.com/resource/pubmed/chemical/Propranolol,
http://linkedlifedata.com/resource/pubmed/chemical/Sodium
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pubmed:status |
MEDLINE
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pubmed:month |
Feb
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pubmed:issn |
0002-9513
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
266
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
H377-83
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pubmed:dateRevised |
2007-11-14
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pubmed:meshHeading |
pubmed-meshheading:8141337-4,4'-Diisothiocyanostilbene-2,2'-Disulfonic Acid,
pubmed-meshheading:8141337-Amiloride,
pubmed-meshheading:8141337-Analysis of Variance,
pubmed-meshheading:8141337-Animals,
pubmed-meshheading:8141337-Bicarbonates,
pubmed-meshheading:8141337-Cerebral Arteries,
pubmed-meshheading:8141337-Cimetidine,
pubmed-meshheading:8141337-Histamine,
pubmed-meshheading:8141337-Isometric Contraction,
pubmed-meshheading:8141337-Meglumine,
pubmed-meshheading:8141337-Monensin,
pubmed-meshheading:8141337-Mouth,
pubmed-meshheading:8141337-Muscle, Smooth, Vascular,
pubmed-meshheading:8141337-Muscle Tonus,
pubmed-meshheading:8141337-Nifedipine,
pubmed-meshheading:8141337-Norepinephrine,
pubmed-meshheading:8141337-Ouabain,
pubmed-meshheading:8141337-Propranolol,
pubmed-meshheading:8141337-Rabbits,
pubmed-meshheading:8141337-Sodium,
pubmed-meshheading:8141337-Veins
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pubmed:year |
1994
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pubmed:articleTitle |
Myogenic tone of rabbit facial vein and posterior cerebral artery is influenced by changes in extracellular sodium.
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pubmed:affiliation |
Department of Pharmacology, College of Medicine, University of Vermont, Burlington 05405-0068.
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pubmed:publicationType |
Journal Article,
In Vitro,
Research Support, U.S. Gov't, P.H.S.
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