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PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1993-3-23
pubmed:abstractText
The contribution of cytochrome P-450 metabolites of arachidonic acid in elevating vascular tone in the kidneys of adult spontaneously hypertensive rats (SHR) and Wistar-Kyoto (WKY) rats was examined using a juxtamedullary nephron microvascular preparation perfused in vitro with a physiological salt solution containing 5% albumin. At 80 mm Hg, the basal internal diameters of arcuate and interlobular arteries and proximal and distal afferent arterioles of the SHR averaged 341 +/- 15.81 +/- 5.24 +/- 0.5 and 19 +/- 0.3 micron, respectively. These diameters were 5-29% smaller (p < 0.05) than those measured in corresponding vessels in WKY rats. Addition of the P-450 inhibitors, ketoconazole (100 microM) or 17-octadecynoic acid (17-ODYA, 20 microM), to the perfusate and bath increased the diameters of the preglomerular vasculature of the SHR by 6-29%, but by only 3-13% in WKY rats and reduced significantly the differences in pressure-diameter relations between the two groups. The rate of formation of 20-hydroxyeicosatetraenoic acid (20-HETE) by renal cortical microsomes was similar in SHR and WKY rats. However, the production of epoxyeicosatrienoic acids (EETs) by cortical microsomes was 87% lower and dihydroxyeicosatrienoic acids (DHETs) 70% higher in the SHR than WKY rats. Ketoconazole (100 microM) reduced the formation of 20-HETE by 80%, and EETs and DHETs production by more than 98% in SHR and WKY rats. 17-ODYA (20 microM) reduced the formation of 20-HETE, EETs and DHETs by more than 98% in both groups. These results suggest that cytochrome P-450 metabolites of arachidonic acid contribute to the elevated renal vascular tone in adult SHR. This may be due to an enhanced vascular responsiveness to vasoconstrictor P-450 metabolites in SHR or an elevated local production of vasoconstrictor eicosanoids in the renal vasculature of SHR rather than in renal cortical tissue.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:issn
1018-1172
pubmed:author
pubmed:issnType
Print
pubmed:volume
30
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
53-60
pubmed:dateRevised
2003-11-14
pubmed:meshHeading
pubmed:articleTitle
Role of cytochrome P-450 in elevating renal vascular tone in spontaneously hypertensive rats.
pubmed:affiliation
Department of Physiology, Medical College of Wisconsin, Milwaukee 53226.
pubmed:publicationType
Journal Article