UTILIZATION OF GLUCOSE AND FRUCTOSE IN RESTING METABOLISM OF CALLIPHORA ERYTHROCEPHALA

The carbohydrates in acid extracts of males of Calliphora erythrocephala were analyzed qualitatively and quantitatively by paper chromatography, thin-layer chromatography, enzymatic procedures, and the Anthron method. The most important fractions are glucose, fructose, trehalose, and glycogen. After injection of glucose and fructose (unlabelled or iniformely labelled with 14C) into hungry flies the changes in amount of the 4 main carbohydrates in relation to time was measured. Results: 1. Glucose and fructose, apart from entering the glycolytic pathway, are completely converted to trehalose and glycogen (Figs. 1-4). 2. The rate of trehalose formation is much higher in flies 18 to 20 days old than in flies 11 oto 15 days old. There is no such difference in the synthesis of glycogen (Figs. 1-4). 3. Glucose is an important intermediate in the conversion of fructose to trehalose and glycogen (Table 1; Figs. 3 and 4). The possible pathways from fructose to glucose are discussed. © 1969 Springer-Verlag.