Glycogen Formation in Rats After Administration of Diets High in Galactose,Glucose,and Lactose

Abstract

It has been shown 1 that galactose exerts a greater ketolytic action than does glucose when administered to fasting humans or to subjects on a protein-fat diet. Moreover, a superior nitrogen sparing action was usually noted after the ingestion of galactose than that found after a similar amount of glucose. In both cases the better effect of galactose was demonstrated not only by the lower level to which these constituents were depressed but also by the more prolonged persistence of the effect. One explanation for this discrepancy is that the glycogen content of the animal may remain at a higher level for a longer time after galactose than after glucose administration. Cori, 2 however, found that galactose was a very poor glycogen former in rats as compared with glucose although he made no studies at longer than 4-hour intervals after the sugars were fed.

This investigation was made to ascertain the quantitative relationships in glycogen storage when longer periods of starvation had elapsed following the administration of diets high in glucose, galactose, lactose, or a mixture of glucose and galactose. Besides the sugar under investigation which comprised 44 to 46% of the diet, casein (20%), yeast (10%), lard (20%), salt (4%), and cellu (2%) made up the food. Adult male rats were used. Three rats of each group of 6 served as controls, while the remaining ones were fed galactose after an appropriate period of fasting following the administration of the above diet. The galactose was fed by stomach tube in 50% solution in a dose of 0.50 gm. per 100 sq. cm. of body surface. The control animals were killed at the same time as the galactose fed ones.