Regulation of hepatic lipogenesis by dietary maize oil or tripalmitin in the meal-fed mouse

Abstract

The effect of varying dietary levels of maize oil and tripalmitin (0–250 g fat/kg) on hepatic lipogenesis and the levels of hepatic fatty acid synthetase (FAS), glucose-6-phosphate dehydrogenase ( EC 1.1.1.49; G6PD), malic enzyme ( EC 1.1.1.38, 1.1.1.39, 1.1.1.40; ME) and glucokinase ( EC 2.7.1.2; GK) was examined in meal-fed mice. 2. Meal-fed mice compared to mice fed ad lib. show enhanced hepatic lipogenesis as demonstrated by an increased rate of in vivo fatty acid synthesis and increased levels of FAS, ME and G6PD. The level of GK in meal-fed mice was unchanged by meal feeding. 3. Maize oil more effectively reduced in vivo hepatic lipogenesis than tripalmitin in meal-fed mice.4. Maize oil more effectively reduced the hepatic levels of FAS, G6PD, ME and GK than tripalmitin in meal-fed mice.5. The increased inhibition by maize oil is observed at all levels of fat in the diet investigated and has been shown not to be due to decreased carbohydrate intake nor to differences between the absorption of maize oil and tripalmitin.