Glucose Metabolism of Pancreatic Islets Isolated from Neonatal Rats[*]

Abstract

It has been shown previously that glucose does not stimulate insulin release from pancreatic islets of fetal and neonatal rats. In the present study the oxygen consumption, the glucose oxidation and the rates of anaerobic glycolysis have been compared in islets from newborn rats and in glucose-sensitive islets from 6 days old rats. When incubated in medium containing 3.3 mM glucose the islets from newborn rats showed higher rates of oxygen consumption and glucose oxidation than those of the older rats. In both age groups the oxidation of glucose was considerably enhanced, when the extracellular glucose concentration was raised to 16.7 mM. A corresponding increase in the respiratory rate was observed only in the older animals. Stimulation of the anaerobic glycolytic rate by 16.7 mM glucose was most pronounced in the younger animal group. The results indicate that the lack of stimulation of insulin release by glucose should not primarily be ascribed to overall deficiencies in the uptake, phosphorylation or oxidation of glucose by the fetal B-cell.

Key words

Isolated Pancreatic Islets - Islet Glucose Metabolism - Neonatal Rats - Insulin Secretion

1 This work was supported by the Swedish Medical Research Council (B71-12X-109-07C), the Medical Faculty of the University of Uppsala, the Swedish Diabetes Association, Expresses Prenatalforskningsfond and the United States Public Health Service (AM-12535).

1 This work was supported by the Swedish Medical Research Council (B71-12X-109-07C), the Medical Faculty of the University of Uppsala, the Swedish Diabetes Association, Expresses Prenatalforskningsfond and the United States Public Health Service (AM-12535).