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Nitric oxide, islet acid glucan-1,4-alpha-glucosidase activity and nutrient-stimulated insulin secretion

Mosén, Henrik LU ; Salehi, S Albert LU and Lundquist, Ingmar LU (2000) In Journal of Endocrinology 165(2). p.293-300
Abstract
The mechanism of nutrient-evoked insulin release is clearly complex. One part of that mechanism is postulated to be the activation of the glycogenolytic enzyme acid glucan-1,4-alpha-glucosidase. As nitric oxide (NO) has been found to be a potent inhibitor of glucose-stimulated insulin secretion, we have now investigated a possible influence of exogenous NO and inhibition of endogenous NO production on islet acid glucan-1,4-alpha-glucosidase activity in relation to insulin release stimulated by glucose and l-arginine. In isolated islets, NO derived from the intracellular NO donor hydroxylamine inhibited the activation of acid glucan-1, 4-alpha-glucosidase and its isoform acid alpha-glucosidase in parallel with inhibition of... (More)
The mechanism of nutrient-evoked insulin release is clearly complex. One part of that mechanism is postulated to be the activation of the glycogenolytic enzyme acid glucan-1,4-alpha-glucosidase. As nitric oxide (NO) has been found to be a potent inhibitor of glucose-stimulated insulin secretion, we have now investigated a possible influence of exogenous NO and inhibition of endogenous NO production on islet acid glucan-1,4-alpha-glucosidase activity in relation to insulin release stimulated by glucose and l-arginine. In isolated islets, NO derived from the intracellular NO donor hydroxylamine inhibited the activation of acid glucan-1, 4-alpha-glucosidase and its isoform acid alpha-glucosidase in parallel with inhibition of glucose-stimulated insulin release. In comparison, other lysosomal enzymes were largely unaffected. Similarly, the spontaneous NO donor sodium nitroprusside, as well as NO gas, when added to islet homogenates, suppressed the activities of these acid alpha-glucosidehydrolases and, to a lesser extent, the activities of other lysosomal enzymes. Finally, in the presence of the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester, insulin release from isolated islets stimulated by glucose or l-arginine was markedly potentiated in parallel with an accompanying increase in the activities of acid glucan-1,4-alpha-glucosidase and acid alpha-glucosidase. Other lysosomal enzymes and neutral alpha-glucosidase were not influenced. We propose that an important inhibitory effect of NO on the insulin secretory processes stimulated by glucose and l-arginine is exerted via inactivation of islet acid glucan-1,4-alpha-glucosidase, a putative key enzyme in nutrient-stimulated insulin release. (Less)
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author
organization
publishing date
type
Contribution to journal
publication status
published
subject
in
Journal of Endocrinology
volume
165
issue
2
pages
293 - 300
publisher
Society for Endocrinology
external identifiers
  • pmid:10810293
ISSN
1479-6805
DOI
10.1677/joe.0.1650293
language
English
LU publication?
yes
id
0d291b18-c0f3-4ffe-8f33-1d3040343d12 (old id 1117838)
date added to LUP
2008-06-25 09:00:18
date last changed
2016-04-15 19:31:02
@article{0d291b18-c0f3-4ffe-8f33-1d3040343d12,
  abstract     = {The mechanism of nutrient-evoked insulin release is clearly complex. One part of that mechanism is postulated to be the activation of the glycogenolytic enzyme acid glucan-1,4-alpha-glucosidase. As nitric oxide (NO) has been found to be a potent inhibitor of glucose-stimulated insulin secretion, we have now investigated a possible influence of exogenous NO and inhibition of endogenous NO production on islet acid glucan-1,4-alpha-glucosidase activity in relation to insulin release stimulated by glucose and l-arginine. In isolated islets, NO derived from the intracellular NO donor hydroxylamine inhibited the activation of acid glucan-1, 4-alpha-glucosidase and its isoform acid alpha-glucosidase in parallel with inhibition of glucose-stimulated insulin release. In comparison, other lysosomal enzymes were largely unaffected. Similarly, the spontaneous NO donor sodium nitroprusside, as well as NO gas, when added to islet homogenates, suppressed the activities of these acid alpha-glucosidehydrolases and, to a lesser extent, the activities of other lysosomal enzymes. Finally, in the presence of the NO synthase inhibitor N(G)-nitro-l-arginine methyl ester, insulin release from isolated islets stimulated by glucose or l-arginine was markedly potentiated in parallel with an accompanying increase in the activities of acid glucan-1,4-alpha-glucosidase and acid alpha-glucosidase. Other lysosomal enzymes and neutral alpha-glucosidase were not influenced. We propose that an important inhibitory effect of NO on the insulin secretory processes stimulated by glucose and l-arginine is exerted via inactivation of islet acid glucan-1,4-alpha-glucosidase, a putative key enzyme in nutrient-stimulated insulin release.},
  author       = {Mosén, Henrik and Salehi, S Albert and Lundquist, Ingmar},
  issn         = {1479-6805},
  language     = {eng},
  number       = {2},
  pages        = {293--300},
  publisher    = {Society for Endocrinology},
  series       = {Journal of Endocrinology},
  title        = {Nitric oxide, islet acid glucan-1,4-alpha-glucosidase activity and nutrient-stimulated insulin secretion},
  url          = {http://dx.doi.org/10.1677/joe.0.1650293},
  volume       = {165},
  year         = {2000},
}