The Effect of Fatty Acids and Ketone Bodies on the Biosynthesis of Insulin in Isolated Pancreatic Islets of Obese Hyperglycemic Mice[*]

Abstract

Collagenase-isolated islets from obese hyperglycemic mice were used to study the effects of fatty acids and ketone bodies on insulin biosynthesis. The biosynthetic rate was quantitated as the incorporation of ³H-leucine into proinsulin and insulin, which were separated from the crude islet homogenates with anti-insulin serum coupled to cyanogen bromide activated Sepharose® 4B. Palmitate and oleate did not stimulate the incorporation into proinsulin and insulin while 16.7 mM glucose caused a nine-fold increase of ³H-leucine incorporation during a 3 h incubation as compared to the basal buffer alone. A weak stimulatory effect was seen with 5 mM octanoate. The ketone bodies had a weak stimulating effect on islet protein biosynthesis, but no preferential stimulus to the insulin biosynthesis was found.

Key words

Insulin Biosynthesis - Long-chain Fatty Acids - Octanoate - Ketone Bodies - Obese Hyperglycemic Mice

1 The present study was supported by grants from the Medical Research Council, the Swedish Diabetes Association, the Swedish Society for Medical Research and the Medical Faculty of Uppsala. The skilfull technical assistance of Miss Ingegerd Kvist is gratefully acknowledged.

1 The present study was supported by grants from the Medical Research Council, the Swedish Diabetes Association, the Swedish Society for Medical Research and the Medical Faculty of Uppsala. The skilfull technical assistance of Miss Ingegerd Kvist is gratefully acknowledged.