Linked Life Data

1357625

Source:http://linkedlifedata.com/resource/pubmed/id/1357625

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
4
pubmed:dateCreated
1992-10-29
pubmed:abstractText
Dopamine decreases tubular sodium reabsorption, attributed in part to Na/K-ATPase inhibition in the proximal convoluted tubule (PCT). Because the final regulation of sodium excretion occurs in the collecting duct, where we have demonstrated specific dopamine DA1 binding sites, we examined the effects of dopamine, and of DA1 and DA2 receptor agonists on the Na/K pump in the microdissected rat cortical collecting duct (CCD) and in Madin-Darby canine kidney (MDCK) cells, a line derived from the dog distal nephron. Dopamine inhibited pump activity in CCD by approximately 40%-50%, an effect proportionally larger than in the PCT. Unlike in the latter, the effect of dopamine was reproduced by the DA1 agonist fenoldopam, which inhibited the CCD pump in dose-dependent manner (maximum, 10 microM). The DA2 agonist quinpirole was without effect, either alone or in combination with fenoldopam. These actions on Na/K-ATPase paralleled in reciprocal fashion effects on adenylate cyclase: dopamine or fenoldopam, but not quinpirole, produced a significant increase in cAMP content, and the stimulation by dopamine was blocked by SCH 23390. Inhibitors of cAMP phosphodiesterase (3-isobutyl-1-methyl-xanthine and theophylline), as well as forskolin and dibutyryl-cAMP, mimicked the effect of dopamine on the pump, underscoring the role of increased cAMP in this phenomenon. Both dopamine and fenoldopam inhibited Na/K-ATPase activity in MDCK cells. The results indicate that besides the PCT dopamine inhibits Na/K-ATPase activity in cells of the distal nephron, where its effect on the pump appears to be more pronounced and is mediated by activation of the DA1 receptor. The natriuretic effect of dopamine is probably exerted at both proximal and distal nephron sites.
pubmed:grant
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Jul
pubmed:issn
0031-6768
pubmed:author
pubmed:issnType
Print
pubmed:volume
421
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
302-6
pubmed:dateRevised
2007-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Dopamine inhibits Na/K-ATPase in single tubules and cultured cells from distal nephron.
pubmed:affiliation
Department of Medicine, University of Chicago Pritzker School of Medicine, Illinois 60637.
pubmed:publicationType
Journal Article, Research Support, U.S. Gov't, P.H.S., Research Support, Non-U.S. Gov't