Linked Life Data

2837094

Source:http://linkedlifedata.com/resource/pubmed/id/2837094

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
6 Pt 1
pubmed:dateCreated
1988-7-8
pubmed:abstractText
We have studied the kinetic properties of basal and angiotensin II (ANG II)-stimulated Na+-H+ exchange in cultured rat aortic smooth muscle cells. Initial rates of 22Na+ influx were measured in the presence of ouabain (1 mM) and bumetanide (0.1 mM) with and without amiloride after intracellular acidification by preincubation in Na-free media. The kinetics of amiloride (100 microM)-sensitive Na+ influx were studied under the following conditions: 1) constant intracellular pH (pHi; 6.8) and varying external Na+ (Na+o), which gave a Km of 23.6 +/- 2.0 (SD, n = 3) mM and a maximum velocity (Vmax) of 25 nmol.mg protein-1.min-1 (varying the amiloride concentration gave a Ki of 22 microM for inhibition under these conditions); and 2) constant Na+o (100 mM) and varying pHi (from 7.4 to 6.2), which indicated that amiloride-sensitive Na+ influx was stimulated by cell acidification when an outward H+ gradient was imposed. ANG II-stimulated amiloride-sensitive Na+ influx for up to 30 min with a half-maximal activation 10(-8) M. The pHi dependence from cell pH (pHi 7.2-6.2) of amiloride-sensitive Na+ influx stimulated by ANG II was similar to that of the basal values, a finding indicating that ANG II did not change the affinity of Na+-H+ exchange for intracellular H+. However, at pHi 6.8, ANG II increased the Vmax of amiloride-sensitive Na+ influx from 25 to 33 nmol.mg protein-1.min-1 and markedly decreased the Km for Na+o from 23.6 +/- 7.4 to 3.7 (SD, n = 4; P less than 0.005) mM.(ABSTRACT TRUNCATED AT 250 WORDS)
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jun
pubmed:issn
0002-9513
pubmed:author
pubmed:issnType
Print
pubmed:volume
254
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
C751-8
pubmed:dateRevised
2007-11-14
pubmed:meshHeading
pubmed:year
1988
pubmed:articleTitle
Vascular smooth muscle Na+-H+ exchanger kinetics and its activation by angiotensin II.
pubmed:affiliation
Department of Medicine, Brigham and Women's Hospital, Boston, Massachusetts 02115.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S.