Linked Life Data

10224088

Source:http://linkedlifedata.com/resource/pubmed/id/10224088

Statements in which the resource exists as a subject.
PredicateObject
rdf:type
lifeskim:mentions
pubmed:issue
19
pubmed:dateCreated
1999-6-3
pubmed:abstractText
Increases in the concentration of free ATP within the islet beta-cell may couple elevations in blood glucose to insulin release by closing ATP-sensitive K+ (KATP) channels and activating Ca2+ influx. Here, we use recombinant targeted luciferases and photon counting imaging to monitor changes in free [ATP] in subdomains of single living MIN6 and primary beta-cells. Resting [ATP] in the cytosol ([ATP]c), in the mitochondrial matrix ([ATP]m), and beneath the plasma membrane ([ATP]pm) were similar ( approximately 1 mM). Elevations in extracellular glucose concentration (3-30 mM) increased free [ATP] in each domain with distinct kinetics. Thus, sustained increases in [ATP]m and [ATP]pm were observed, but only a transient increase in [ATP]c. However, detectable increases in [ATP]c and [ATP]pm, but not [ATP]m, required extracellular Ca2+. Enhancement of glucose-induced Ca2+ influx with high [K+] had little effect on the apparent [ATP]c and [ATP]m increases but augmented the [ATP]pm increase. Underlying these changes, glucose increased the mitochondrial proton motive force, an effect mimicked by high [K+]. These data support a model in which glucose increases [ATP]m both through enhanced substrate supply and by progressive Ca2+-dependent activation of mitochondrial enzymes. This may then lead to a privileged elevation of [ATP]pm, which may be essential for the sustained closure of KATP channels. Luciferase imaging would appear to be a useful new tool for dynamic in vivo imaging of free ATP concentration.
pubmed:language
eng
pubmed:journal
pubmed:citationSubset
IM
pubmed:chemical
pubmed:status
MEDLINE
pubmed:month
May
pubmed:issn
0021-9258
pubmed:author
pubmed:issnType
Print
pubmed:day
7
pubmed:volume
274
pubmed:owner
NLM
pubmed:authorsComplete
Y
pubmed:pagination
13281-91
pubmed:dateRevised
2006-11-15
pubmed:meshHeading
pubmed:year
1999
pubmed:articleTitle
Glucose generates sub-plasma membrane ATP microdomains in single islet beta-cells. Potential role for strategically located mitochondria.
pubmed:affiliation
Department of Biochemistry, School of Medical Sciences, University of Bristol, Bristol BS8 1TD, United Kingdom.
pubmed:publicationType
Journal Article, Research Support, Non-U.S. Gov't