Linked Life Data

1999160

Source:http://linkedlifedata.com/resource/pubmed/id/1999160

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
3
pubmed:dateCreated
1991-4-10
pubmed:abstractText
Inside-out plasma membrane vesicles from a glucose-responsive rat insulinoma showed an ATP- and Mg2(+)-dependent uptake of Ca2+. The Km (concentration giving half-maximal activity) for Ca2+ was 60 nM. In the presence of 0.4 microM free Ca2+, the Km for ATP was 15 microM, and the Km for Mg2+ was 4 microM. Glucose (30 mM) decreased Ca2+ uptake by 50%, while other insulin secretagogues had no effect, except for glyceraldehyde, which stimulated Ca2+ uptake. Calmodulin increased the uptake of Ca2+, while trifluoperazine and vanadate inhibited the uptake. The Ca2(+)- and Mg2(+)-dependent ATPase from this tumor has a 10- to 20-fold higher requirement for Ca2+, which suggests that this enzyme is not responsible for Ca2+ transport, rather, Ca2+ transport activity represents only a small fraction of the total Ca2(+)-ATPase activity. The physiological importance of Ca2+ transport in insulin secretion is evident from the inhibition of Ca2+ uptake by glucose, which leads to a decrease in Ca2+ efflux from the cell. This inhibition would lead to an increase in intracellular free Ca2+ and insulin release.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
AIM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Mar
pubmed:issn
0013-7227
pubmed:author
pubmed:issnType
Print
pubmed:volume
128
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
1381-4
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1991
pubmed:articleTitle
Calcium transport by plasma membranes from a glucose-responsive rat insulinoma.
pubmed:affiliation
Department of Physiology and Pharmacology, University of Georgia College of Veterinary Medicine, Athens 30602.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't