[The fructose induced "glycogenosis". II. Histochemical studies of glycogen metabolism in rat liver after fructose overload and similar diets (author's transl)].

INTRODUCTION

Feeding of fructose for 7 days has been morphometrically shown to induce a SER-reduction and an accumulation of glycogen in rat liver cells. This hypothetical model "glycogenosis" is investigated with histochemical methods.

MATERIAL AND METHODS

Rats are given a solution of 60% fructose in water as only nutritional source. Controls are given a solution of 60% glucose in water, an isocaloric Altromin-R-standard diet and an Altromin-R-standard diet ad libitum. Reversion of fructose induced metabolic changes is investigated by a 7 days fructose diet followed by an 1-4 days Altromin-R-standard diet ad libitum. Glycogen and glycogen metabolizing enzymes are demonstrated after a 7 days diet and in the course of an 1-7 days fructose diet.

RESULTS AND DISCUSSION

Feeding of fructose leads to a high glycogen content, combined with a high activity of glycogen-phosphorylase and glucose-6-phosphatase in the liver parenchyma. Glycogen-synthetase activity increases during the first 4 days and then it drops to a low level. A pathological alteration of liver cell metabolism seems to be improbable, for all fructose induced changes are reversibel after 2 days of Altromin-R-standard diet. Glucose-6-phosphatase, as a marker-enzyme of the smooth endoplasmatic reticulum, is discussed to become activated by disruption of SER membranes due to fructose.