Metabolism of fatty acids and the levels of ketone bodies in the livers of pyridoxine-deficient rats.

Lipid metabolism was examined in rats fed a high-protein pyridoxine-deficient diet, and their livers were found to contain large amounts of lipids, mainly in the forms of triglycerides and cholesteryl ester. The contents of ketone bodies in the livers of pyridoxine-deficient and the control rats were similar. Their NAD+/NADH ratios, calculated from the amounts of ketone bodies, were also similar in pyridoxine-deficient and control groups when the animals were fed, but the ratio in pyridoxine-deficient rats was lower than that of control rats when the animals were starved. After injection of 14C-linoleic acid, the amounts of expired 14CO2 in pyridoxine-deficient and control rats were similar. The pattern of incorporations of 14C-linoleic acid into various lipid components of the livers were examined; incorporation into the phospho-lipid fraction was similar in control and deficient rats, but the incorporation into the triglyceride fraction was slower, and the incorporation into cholesterol was faster in deficient animals than in controls.