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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
5 Pt 2
pubmed:dateCreated
1992-12-22
pubmed:abstractText
Based on evidence that extracellular ATP can influence vascular smooth muscle function in other organ systems, experiments were conducted to characterize the responsiveness of rat juxtamedullary microvascular segments to ATP. Experiments were performed using the in vitro blood-perfused juxtamedullary nephron preparation combined with video microscopy. Pentobarbital-anesthetized rats were pretreated with enalaprilat (2 mg iv) for 30 min before the right kidney was isolated and prepared for study. Renal perfusion pressure was set at 110 mmHg and held constant. Under control conditions, afferent and efferent arteriolar diameters averaged 19.9 +/- 1.4 (n = 19) and 21.6 +/- 1.2 microns (n = 10), respectively. Superfusion with 1, 10, and 100 microM ATP solutions induced sustained dose-dependent afferent vasoconstriction of 8.3 +/- 1.4, 12.8 +/- 1.7, and 12.1 +/- 2.1%, respectively (P < 0.01). Afferent vasoconstrictor responses to ATP were also observed during adenosine receptor blockade. In contrast, efferent arterioles were unresponsive to ATP stimulation even at concentrations as high as 100 microM (P > 0.05). Arcuate and interlobular arterial diameters averaged 82.0 +/- 15.7 (n = 5) and 43.4 +/- 4.5 microns (n = 6), respectively, during control conditions and responded to ATP treatment with a transient vasoconstriction followed by a gradual return to control diameter. Interlobular arteries exhibited a sustained constriction only at the 100 microM concentration (P < 0.05). These data demonstrate that afferent arterioles are more responsive to ATP treatment than other renal microvascular segments and suggest the presence of ATP-sensitive P2x purinoceptors on pre- but not postglomerular juxtamedullary microvascular elements.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Nov
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
263
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
F886-93
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Effects of ATP on pre- and postglomerular juxtamedullary microvasculature.
pubmed:affiliation
Department of Physiology, Tulane University School of Medicine, New Orleans, Louisiana 70112.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't