EFFECTS OF VARIOUS DIETARY FATTY-ACIDS ON ALPHA-AMINO-BETA-CARBOXYMUCONATE-EPSILON-SEMIALDEHYDE DECARBOXYLASE ACTIVITY IN RAT-LIVER

In this study, we investigated the effects of short-chain, middle-chain, and long-chain fatty acids on the activity of rat liver alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase [EC 4.1.1.451 (ACMSD), a key enzyme of tryptophan-niacin metabolism. Moreover, we examined the cholesterol metabolism and lipid peroxidation in relation to ACMSD activity in rats. When diets containing 2%, 5%, and 10% levels of fatty acids were given to rats for a week, saturated fatty acids and elaidic acid (trans form) did not suppress the ACMSD activity in liver. But polyunsaturated fatty acids such as linoleic acid, linolenic acid, eicosapentaenoic acid (EPA), and docosahexaenoic acid (DHA) strongly suppressed the liver ACMSD activity. Five % sorbic acid and oleic acid tended to suppress the liver ACMSD activity weakly. On the other hand, this report indicated that there is no correlation between liver ACMSD activity and cholesterol levels of serum or liver, but there is a weak negative correlation between liver malondialdehyde concentration and liver ACMSD specific activity.