Long-term effects of glibenclamide on the insulin production, oxidative metabolism and quantitative ultrastructure of mouse pancreatic islets maintained in tissue culture at different glucose concentrations

Rates of glucose oxidation and insulin release in response to a wide range of glucose concentrations were studied in short-term experiments in isolated mouse pancreatic islets maintained in tissue culture for 6 days at either a physiological glucose concentration (6.7mm) or at a high glucose concentration (28mm). The curves relating glucose oxidation or insulin release to the extracellular glucose concentration obtained with islets cultured in 6.7mm-glucose displayed a sigmoid shape similar to that observed for freshly isolated non-cultured islets. By contrast islets that had been cultured in 28mm-glucose showed a linear relationship between the rate of glucose oxidation and the extracellular glucose concentration up to about 8mm-glucose. The maximal oxidative rate was twice that of the non-cultured islets and the glucose concentration associated with the half-maximal rate considerably decreased. In islets cultured at 28mm-glucose there was only a small increase in the insulin release in response to glucose, probably due to a depletion of stored insulin in those B cells that had been cultured in a high-glucose medium. It is concluded that exposure of B cells for 6 days to a glucose concentration comparable with that found in diabetic individuals causes adaptive metabolic alterations rather than degeneration of these cells.

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Glucose dependent alterations of mitochondrial ultrastructure and enzyme content in mouse pancreatic islets maintained in tissue culture

Cell and Tissue Research ◽

10.1007/bf00220177 ◽

1975 ◽

Vol 162 (3) ◽

Cited By ~ 10

Author(s):

L.A.H. Borg ◽

A. Andersson ◽

C. Berne ◽

J. Westman

Keyword(s):

Tissue Culture ◽

Pancreatic Islets ◽

Mitochondrial Ultrastructure ◽

Enzyme Content ◽

Mouse Pancreatic Islets

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Opposite effects of starvation on oxidation of [14C]adenosine and adenosine-induced insulin release by isolated mouse pancreatic islets

Biochemical Journal ◽

10.1042/bj1760619 ◽

1978 ◽

Vol 176 (2) ◽

pp. 619-621 ◽

Cited By ~ 4

Author(s):

A Andersson

Keyword(s):

Insulin Secretion ◽

Pancreatic Islets ◽

Insulin Release ◽

Metabolic Flux ◽

Insulin Biosynthesis ◽

Insulin Production ◽

Stimulate Insulin Secretion ◽

Mouse Pancreatic Islets

To test further the hypothesis that ribonucleosides stimulate insulin secretion and biosynthesis by producing metabolic signals, the effects of starvation on adenosine-stimulated insulin production and the oxidation of adenosine by isolated mouse pancreatic islets were examined. No direct correlation was found between the metabolic flux and insulin secretion, since the starvation-induced impairment of the adenosine-stimulated insulin secretion was accompanied by an increased rate of adenosine oxidation. Adenosine-stimulated insulin biosynthesis was, however, unaffected by starvation.

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