Linked Life Data

2294962

Source:http://linkedlifedata.com/resource/pubmed/id/2294962

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
1
pubmed:dateCreated
1990-2-20
pubmed:abstractText
This paper describes experiments to examine Rb+ fluxes via the Na+/K+/Cl- cotransporter in membrane vesicles from renal outer medulla of three strains of rat: (A) Wistar (B) Milan hypertensive (MHS) and normotensive (MNS), and (C) Sabra salt-sensitive hypertensive (SBH) and salt-resistant (SBN). Initially, Na(+)-dependent furosemide- or bumetanide-inhibited 86Rb+ fluxes were characterised using Wistar rat microsomes. The latter were partially purified on a metrizamide cushion, and assay conditions were optimized for use with microsomes from the other rats. The major result is that in microsomes from adult Milan hypertensive (MHS) rats the rate of the Na+/K+/Cl(-)-cotransporter mediated 86Rb flux at sub-saturating concentrations of Rb, appears to be significantly greater than in the normotensive (MNS) controls. The effect reflects an increased apparent Rb affinity of the cotransporter in MHS microsomes. There is no difference in maximal rate or in the apparent Na+ activation affinity of the 86Rb+ flux. In addition bumetanide appears to be a somewhat more effective inhibitor in MHS compared to MNS microsomes. The 86Rb+ flux result is compatible with a previous finding that in red cells, Na+/K+ -cotransporter mediated fluxes are increased in MHS compared to MNS. It supports the notion that the Na+/K+/Cl(-)-cotransporter in in both red cells and kidney is a genetic marker for hypertension. It is of interest that apparently more than one Na+ transport system is affected in MHS hypertensive kidneys (a) the Na+/K+/Cl- cotransporter in the thick ascending limb of Henle and (b) the Na+/H+ exchanger and/o a conductive Na(+)-pathway in brush-border membranes from proximal tubule. It is conceivable that in the hypertensive animals a common regulatory pathway (e.g., phosphorylation) or protein (e.g., cytoskeleton) is affected along the length of the nephron. In Sabra SBH and SBN rat microsomes, no difference was found for the 86Rb+ flux via the Na+/K+/Cl- cotransporter (or via a K+ channel).
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jan
pubmed:issn
0006-3002
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
1021
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1990
pubmed:articleTitle
Na+/K+/Cl(-)-cotransporter mediated Rb+ fluxes in membrane vesicles from kidneys of normotensive and hypertensive rats.
pubmed:affiliation
Istituto Ricerche Farmitalia Carlo Erba, Nerviano, Milano, Italy.
pubmed:publicationType
Journal Article, In Vitro, Research Support, U.S. Gov't, Non-P.H.S., Research Support, Non-U.S. Gov't