ESTIMATION OF THE FERMENTABLE CARBOHYDRATES IN RABBIT LIVER

¹ The Department of Physiology, University of Aberdeen

1. Estimation of glycogen and free sugar failed by 25 ± 8 per cent. to account for all of the fermentable carbohydrate in rabbit liver. The deficiency was attributed to the presence of a fermentable polysaccharide which was destroyed during the glycogen determination and was insoluble in 90 per cent. alcohol. It was extracted from liver by 32 per cent. alcohol.

2. The only copper-reducing substance extracted from liver by 90 per cent. alcohol agreed, in its optical rotation and copper-reducing power, with glucose, which is in all probability the "free sugar" of the liver.

3. At death the "free sugar" content of liver, expressed as glucose, was not more than 0·2 per cent., but subsequent to death it rapidly increased. This increase was accompanied by a nearly equivalent decrease in the percentage amount of glycogen.

The author wishes to acknowledge his indebtedness to Professor J. J. R. MacLeod, who suggested this work, and to the Carnegie Trust for a Teaching Fellowship.