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Predicate | Object |
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rdf:type | |
lifeskim:mentions | |
pubmed:issue |
2
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pubmed:dateCreated |
1986-9-17
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pubmed:abstractText |
A new sequential gating perifusion technique was employed to investigate secretion vesicle margination and granule lysis in islets isolated from 2- and 18-month-old Fischer 344 rats. The technique is based on sequential perifusion (periods A, B, and C) of isolated islets with glucose (30, 165, or 300 mg/dl) in the presence of sodium isethionate, an inhibitor of granule lysis, followed thereafter by trifluoperazine, an inhibitor of secretion vesicle margination, and glucose (300 mg/dl) or isobutylmethylxanthine (IBMX; 400 microM). When glucose was employed during period A to marginate secretion vesicles to the plasma membrane, subsequent glucose- and IBMX-induced insulin release (period C) was depressed in islets from 18-month-old rats [maximal increase above the basal rate of release (delta max), 9 +/- 2 nU/micron X min] compared to that in the 2-month-old animals (delta max, -19 +/- 3 nU/micron X min). With glyburide (400 microM) used to induce secretion vesicle margination, glucose- and IBMX-induced insulin release was the same in young and old animals (delta max, 14 +/- 3 and 15 +/- 3 nU/micron X min, respectively). Insulin release was then studied as a function of secretion vesicle margination at the plasma membrane by measuring somatostatin (SRIF) receptor recruitment. The islets from older animals must be stimulated with 300 mg/dl glucose to attain the same level of SRIF binding as in islets isolated from younger animals stimulated with 150-165 mg/dl glucose. Insulin release per unit SRIF binding was identical in young and old animals (65 and 69 nU/liter fmol SRIF binding), indicating normal lysis of marginated secretion granules. These studies implicate glucose-induced secretion vesicle margination as the site of impairment in age-related insulin release.
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pubmed:grant | |
pubmed:language |
eng
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pubmed:journal | |
pubmed:citationSubset |
AIM
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pubmed:chemical | |
pubmed:status |
MEDLINE
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pubmed:month |
Aug
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pubmed:issn |
0013-7227
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pubmed:author | |
pubmed:issnType |
Print
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pubmed:volume |
119
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pubmed:owner |
NLM
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pubmed:authorsComplete |
Y
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pubmed:pagination |
827-32
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pubmed:dateRevised |
2011-11-17
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pubmed:meshHeading |
pubmed-meshheading:2426091-1-Methyl-3-isobutylxanthine,
pubmed-meshheading:2426091-Aging,
pubmed-meshheading:2426091-Animals,
pubmed-meshheading:2426091-Cytoplasmic Granules,
pubmed-meshheading:2426091-Glucose,
pubmed-meshheading:2426091-Insulin,
pubmed-meshheading:2426091-Islets of Langerhans,
pubmed-meshheading:2426091-Male,
pubmed-meshheading:2426091-Rats,
pubmed-meshheading:2426091-Rats, Inbred F344,
pubmed-meshheading:2426091-Somatostatin
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pubmed:year |
1986
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pubmed:articleTitle |
Insulin secretion in aging: studies with sequential gating of secretion vesicle margination and lysis.
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pubmed:publicationType |
Journal Article,
Comparative Study,
In Vitro,
Research Support, U.S. Gov't, P.H.S.,
Research Support, U.S. Gov't, Non-P.H.S.,
Research Support, Non-U.S. Gov't
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