ISSN:
1432-0428
Keywords:
Glucose metabolism
;
islet adenosine-5-triphosphate
;
insulin release
;
intermediary metabolism
;
microperifusion
;
ob/ob-mice
;
pancreaticβ-cells. starvation
;
TCM 199
;
theophylline
Source:
Springer Online Journal Archives 1860-2000
Topics:
Medicine
Notes:
Summary Microperifusion was used to study the dynamics of insulin release and metabolic changes in pancreatic islets microdissected fromob/ob-mice. When the islets were suddenly exposed to a high glucose concentration, their content of glucose-6-phosphate and fructose-1, 6-diphosphate started to rise immediately, whereas a secretory response was not observed until after about 80 sec. This is consistent with the hypothesis that glucose metabolism initiates insulin release. Fasting the donor animals for 18 h reduced the initial phase of glucose-stimulated release but left the rise of glucose-6-phosphate, as well as the late phase of sustained release, unaffected. The use of a tissue culture medium (TCM 199) instead of Krebs-Ringer bicarbonate buffer as the basal medium increased the secretory responses to glucose, particularly the initial phase, both in islets from fed and fasted mice. However, the difference between fed and fasted mice remained. Theophylline did not restore the impaired initial secretory response after fasting. The responses of islet fructose-1,6-diphosphate and adenosine-5-triphosphate to glucose depended on the nutritional state of the animals and on the type of basal medium. No consistent correlation was observed between the changes of these substrates and the dynamics of insulin release.
Type of Medium:
Electronic Resource
URL:
http://dx.doi.org/10.1007/BF01239437
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