Effects of a high fructose diet on lipogenic enzyme activities in some organs of rats fed ad libitum.

The effect of a high fructose diet on lipogenesis was studied in rats. Male and female rats were divided into three groups and were fed a high carbohydrate diet ad libitum for 4 days: group 1 was fed a high cornstarch diet, group 2 was fed a high fructose diet without starvation, and group 3 was fed a high fructose diet after 2 days of starvation. The activities of lipogenic enzymes, i.e., glucose-6-phosphate dehydrogenase and malic enzyme were assayed in liver, adipose tissue, and small intestine. The lipid content of liver was also determined. On day 4, the lipid content of group 1 was about 45 mg, that of group 2 was about 70 mg, and that of group 3 was about 115 mg (female) and 145 mg (male) per gram of wet weight. Groups 2 and 3 showed significantly higher activity of hepatic malic enzyme than group 1. The activity of intestinal malic enzyme was highest in group 1 and not significantly different between groups 2 and 3. The malic enzyme activity in adipose tissue of females of group 3 was higher than that in either sex of the other groups.