Linked Life Data

10425203

Source:http://linkedlifedata.com/resource/pubmed/id/10425203

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
2
pubmed:dateCreated
1999-9-8
pubmed:abstractText
ATP is the most important factor in glucose-induced insulin secretion in pancreatic beta-cells, but examination of intracellular differences in ATP concentration is difficult because ATP production and consumption occur simultaneously. In the present study, we measured the ATP concentration under the condition of a reduced ATP requirement by omitting extracellular Ca(2+) and inhibiting Na-K ATPase. The ATP concentration in islets incubated with 16.7 mM glucose in the absence of Ca(2+) for 30 min was increased by about 1. 9-fold more than in the presence of Ca(2+). The increment was extracellular Ca(2+)-dependent, and was completely abolished by the metabolic inhibitors dinitrophenol and iodoacetic acid. The Ca channel blockers including nitrendipine and Ni(2+) did not affect the ATP concentration in islets incubated with 16.7 mM glucose in the presence of Ca(2+). However, when thapsigargin and suramin, inhibitors of Ca-ATPase at the endoplasmic reticulum, were added to Ca channel blockers in the presence of ambient Ca(2+), the intraislet ATP content was increased, similarly to that under Ca-free conditions. But thapsigargin did not further augment the ATP concentration in the islet with 16.7 mM glucose in the absence of Ca(2+). On the other hand, the suppression of Na-K ATPase by ouabain rather reduced the ATP concentration augmented by omission of extracellular Ca(2+). In addition, vanadate, a blocker of Ca-ATPase at the plasma membrane, failed to increase the ATP concentration in the islets. These data suggest that the increment of ATP concentration in the absence of Ca(2+) is attributable to the reduced ATP requirement due to stopping of the Ca-ATPase activity at the endoplasmic reticulum, and that the intracellular ATP concentration is differently regulated by Na-K ATPase at plasma membrane and by Ca-ATPase at endoplasmic reticulum.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Aug
pubmed:issn
0006-291X
pubmed:author
pubmed:copyrightInfo
Copyright 1999 Academic Press.
pubmed:issnType
Print
pubmed:day
2
pubmed:volume
261
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
439-44
pubmed:dateRevised
2010-11-18
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Regulation of intracellular ATP concentration under conditions of reduced ATP consumption in pancreatic islets.
pubmed:affiliation
Graduate School of Medicine, Kyoto University, Kyoto, 606-8507, Japan.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't