Linked Life Data

1400388

Source:http://linkedlifedata.com/resource/pubmed/id/1400388

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
29
pubmed:dateCreated
1992-11-18
pubmed:abstractText
Glucose stimulation of insulin release involves metabolism of the sugar and elevation of cytoplasmic calcium (Ca2+i) in pancreatic B-cells. We compared the dynamic changes of metabolism (fluorescence of endogenous reduced pyridine nucleotides, NAD(P)H), membrane potential (intracellular microelectrodes), and Ca2+i (fura-2 technique), in intact mouse islets. Glucose (15 mM) sequentially triggered an increase in NAD(P)H fluorescence, a depolarization with electrical activity, and a rise in Ca2+i. The change in NAD(P)H was monophasic and regular, whereas the changes in membrane potential and Ca2+i were multiphasic, with steady-state regular oscillations of similar average frequencies (about 2.2/min). Digital image analysis revealed that Ca2+i oscillations were synchronous in all regions of the islets. Omission of extracellular Ca2+ abolished the rise in Ca2+i but not the increase in NAD(P)H. Both electrical and Ca2+i oscillations disappeared in low external Ca2+ (1 mM), and became larger but slower in high Ca2+ (10 mM). Sustained depolarization (by tolbutamide, arginine, or high K+) and hyperpolarization (by diazoxide) of B-cells caused sustained increases and decreases of Ca2+i, respectively. In conclusion, the changes in membrane potential induced by various secretagogues trigger synchronous changes in Ca2+i in all B-cells of the islets. The oscillatory pattern of the electrical and Ca2+i responses induced by glucose is not accompanied by and thus probably not due to similar oscillations of metabolism.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
Oct
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
15
pubmed:volume
267
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
20713-20
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1992
pubmed:articleTitle
Influence of membrane potential changes on cytoplasmic Ca2+ concentration in an electrically excitable cell, the insulin-secreting pancreatic B-cell.
pubmed:affiliation
Unité de Diabétologie et Nutrition, University of Louvain Faculty of Medicine, Brussels, Belgium.
pubmed:publicationType
Journal Article, In Vitro, Research Support, Non-U.S. Gov't