Abstract
Adult Swiss ICR male mice were fed fructose or glucose for several days. Glucose-6-phosphatase activity in the duodenal and jejunal epithelium was measured by biochemical and cytophotometric means, and it was also localized cytochemically. The fructose diet stimulated glucose-6-phosphatase activity within 6 hr of feeding. The enzyme was stimulated more in the absorptive cells of the basal third than in those of the median and apical third of the villi. After 3 days of feeding of fructose, the smooth endoplasmic reticulum hypertrophied and occupied large areas in the absorptive cells. Lipoprotein spherules and polymorphic dense bodies were also observed. No such modifications were seen in glucose-fed animals.