Effects of Mannoheptulose on Lipid Metabolism of Rats

Abstract
The effect of mannoheptulose on the hepatic synthesis of fatty acids and cholesterol was studied in young male BHE rats after 3 weeks of feeding a 45% carbohydrate-40% protein diet, a 65% sucrose diet, or a 65% protein diet. Half of the animals fed each diet received daily subcutaneous injections of 20 mg of mannoheptulose (MH) while the remaining animals were given daily injections of isotonic saline. MH treatment enhanced the incorporation of acetate into cholesterol in the animals fed the high protein diet, inhibited the incorporation of acetate into cholesterol in the animals fed the 45% carbohydrate-40% protein diet, and did not affect the incorporation of acetate into cholesterol in the sucrose-fed animals. The activity of fatty acid synthetase was not significantly affeoted by MH treatment. Sucrose-fed animals had the greatest fatty acid synthetase activity whereas the high protein-fed animals had the least enzyme activity. Serum triglyceride levels reflected, in part, the activity of the fatty acid synthetase. The results of these studies show that MH may have a direct effect on lipid metabolism in addition to the short-term effect on insulin release reported by other investigators.