The effect of food deprivation on the activities of some enzymes of the metabolism of carbohydrates in the submandibular salivary glands of rats.

Male albino rats of the Wistar strain were deprived of food, but not water, and killed at various periods. Enzymes of the metabolism of carbohydrates were assayed in the submandibular salivary glands after 24, 48, 72, 96 and 120 hours of starvation. The body weight loss was accompanied by a decrease in gland weight and gland protein content. Blood glucose fells to about 70% the control level. Hexokinase showed no variation with increasing periods of food deprivation. The decrease in the activity of phosphofructokinase was greater than that one observed for glucose-6-phosphate dehydrogenase, indicating a shift in glucose utilization by the cells, from the glycolytic to the pentose phosphate pathway.