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rdf:type |
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lifeskim:mentions |
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pubmed:issue |
4
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pubmed:dateCreated |
1997-7-24
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pubmed:abstractText |
Prolonged exposure of islets to fatty acids results in a lowered glucose set-point for insulin secretion. We examined the mechanism in islets cultured for 24 h with 0.25 mmol/l palmitate. As expected, insulin secretion at 2.8 and 8.3 mmol/l glucose was increased in the palmitate-treated islets as opposed to no change at 27.7 mmol/l glucose. Co-culturing with 0.05 microgram/ml Triacsin C, an inhibitor of long chain acyl-CoA synthetase, blocked this effect. Glucose utilization and oxidation showed the same pattern as insulin secretion, with the step-up for both measurements being fully manifest at 2.8 mmol/l glucose. Glucokinase Km and Vmax measured in islet extracts were unaffected by the palmitate. In contrast, hexokinase Vmax was increased by 25-35% in both the cytoplasmic and mitochondrial-bound pools. Our data suggest prolonged exposure to fatty acids increased beta-cell hexokinase activity, thereby modifying the kinetics of glucose entry into the metabolic pathway and glucose-induced insulin secretion. The cellular mediator is likely an increased level of long chain fatty acyl-CoA esters.
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pubmed:grant |
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pubmed:language |
eng
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pubmed:journal |
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pubmed:citationSubset |
IM
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pubmed:chemical |
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pubmed:status |
MEDLINE
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pubmed:month |
Apr
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pubmed:issn |
0012-186X
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pubmed:author |
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pubmed:issnType |
Print
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pubmed:volume |
40
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
392-7
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pubmed:dateRevised |
2011-11-17
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pubmed:meshHeading |
pubmed-meshheading:9112015-Animals,
pubmed-meshheading:9112015-Cells, Cultured,
pubmed-meshheading:9112015-Coculture Techniques,
pubmed-meshheading:9112015-Coenzyme A Ligases,
pubmed-meshheading:9112015-Cytoplasm,
pubmed-meshheading:9112015-Enzyme Inhibitors,
pubmed-meshheading:9112015-Glucokinase,
pubmed-meshheading:9112015-Glucose,
pubmed-meshheading:9112015-Glycolysis,
pubmed-meshheading:9112015-Hexokinase,
pubmed-meshheading:9112015-Insulin,
pubmed-meshheading:9112015-Islets of Langerhans,
pubmed-meshheading:9112015-Kinetics,
pubmed-meshheading:9112015-Male,
pubmed-meshheading:9112015-Mitochondria,
pubmed-meshheading:9112015-Palmitic Acid,
pubmed-meshheading:9112015-Rats,
pubmed-meshheading:9112015-Rats, Sprague-Dawley,
pubmed-meshheading:9112015-Time Factors,
pubmed-meshheading:9112015-Triazenes
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pubmed:year |
1997
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pubmed:articleTitle |
Beta-cell hypersensitivity to glucose following 24-h exposure of rat islets to fatty acids.
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pubmed:affiliation |
Division of Endocrinology, Diabetes Mellitus, and Molecular Medicine, New England Medical Center, Boston, Massachusetts, USA.
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pubmed:publicationType |
Journal Article,
Research Support, U.S. Gov't, P.H.S.
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