Influence of nicotinic acid on cerebroside synthesis in the brain of developing rats.

The effect of nicotinic acid on synthesis of cerebroside was studied during brain development. Nicotinic acid concentration in the whole brain and liver of rats fed on nicotinic acid-deficient diet for 10 days after weaning was lower than that of animals fed on nicotinic acid-supplemented diet. The cerebroside concentration was markedly lower and the total lipid concentration was slightly lower in the brain of nicotinic acid-deficient animals than in those receiving nicotinic acid-supplemented diet. Therefore, the ratio of cerebrosides to total lipids of nicotinic acid-deficient rats was significantly lower than that of nicotinic acid-supplemented rats. In nicotinic acid-deficient rats, the ratio of long-chain to short-chain fatty acid (C20-24/C14-18) was decreased in the nonhydroxy fatty acid fraction. Moreover, the ratio of synthesis of cerebrosides with hydroxy fatty acid to nonhydroxy fatty acid of nicotinic acid-deficient rats was higher than that of rats fed on nicotinic acid-supplemented diet. These observations suggest that nicotinic acid affects the synthesis of cerebrosides with nonhydroxy fatty acid.