Effect of 3-acetylpyridine on the development of rat brain.

3-Acetylpyridine, an antagonistic agent of nicotinic acid, was given to suckling rats from 6 days of age. Rats were killed at 6, 9, 12, 15, 18, 21, 24, 27 and 30 days of age respectively, and their brains were analyzed for several biochemical parameters of brain growth and myelination for comparison with those of pair-fed and ad libitum control rats. Results of DNA, RNA and protein content measurements in the brain of rats which had received 3-acetylpyridine and of pair-fed control suggested a retardation of about one week in brain growth and development compared to ad libitum control with most striking differences noted at 12 days of age. At 30 days of age, rats which had received 3-acetylpyridine showed lower values in yield of myelin, content of cerebroside and specific activity of 2', 3'-cyclic nucleotide-3-phosphohydrolase, when compared with pair-fed and ad libitum controls. These results indicate that undernourishment due to restricted food intake during brain growth-spurt results in retardation of brain development to some extent. They also suggest that nicotinic acid plays an important role in myelination associated with synthesis of cerebroside which contains high levels of long-chain fatty acid.