Sanada H
J Nutr Sci Vitaminol (Tokyo). 1985 Jun;31(3):327-37. doi: 10.3177/jnsv.31.327.
The effect of dietary fat on the activity of rat liver alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase [EC 4.1.1.45] (ACMSD), a key enzyme of tryptophan-niacin metabolism, was investigated. When high-fat diet was given to rats for a week, the activity of ACMSD in the liver was extremely suppressed, but not in the kidney. The liver enzyme activity was correspondingly and constantly reduced half by increasing soybean oil in the diet in 4% stages. The potency of suppression of the enzyme activity in liver was found to be different between soybean oil and lard in diets. Among various dietary fatty acids, saturated fatty acid was observed to be less effective. Unsaturated fatty acids, however, were shown to be suppressive and polyunsaturated fatty acid such as linoleic and linolenic acids more effective than oleic acid in suppressing liver ACMSD activity. These suppressive effects of dietary unsaturated fatty acids on the liver ACMSD activity were not considered to be caused by their direct effect on the enzyme protein. Moreover, neither inhibitor nor activator was thought to be involved in the alteration of the enzyme activity.
研究了膳食脂肪对大鼠肝脏α-氨基-β-羧基粘康酸-ε-半醛脱羧酶EC 4.1.1.45活性的影响，ACMSD是色氨酸-烟酸代谢的关键酶。给大鼠喂食高脂饮食一周后，肝脏中ACMSD的活性受到极大抑制，但肾脏中的活性未受影响。通过在饮食中以4%的梯度增加大豆油，肝脏酶活性相应且持续地降低了一半。研究发现，饮食中大豆油和猪油对肝脏酶活性的抑制效力不同。在各种膳食脂肪酸中，饱和脂肪酸的效果较差。然而，不饱和脂肪酸具有抑制作用，多不饱和脂肪酸如亚油酸和亚麻酸在抑制肝脏ACMSD活性方面比油酸更有效。膳食不饱和脂肪酸对肝脏ACMSD活性的这些抑制作用被认为不是由它们对酶蛋白的直接作用引起的。此外，酶活性的改变被认为既不涉及抑制剂也不涉及激活剂。
