Send to

Choose Destination
See comment in PubMed Commons below
J Nutr Sci Vitaminol (Tokyo). 1997 Apr;43(2):233-9.

Change of tryptophan-niacin metabolism in D-galactosamine-induced liver injury in rat.

Author information

  • 1Department of Bioproduction Science, Faculty of Horticulture, Chiba University, Matsudo, Japan.


The change of tryptophan-niacin metabolism in D-galactosamine (D-galN) injected rats was investigated. Rats fed with niacin-free diets containing 40% casein for 11 days were injected with D-galN (0.8 g/kg body weight). The urinary excretions of nicotinamide and its metabolites, and the activity of liver alpha-amino-beta-carboxymuconate-epsilon-semialdehyde decarboxylase (ACMSD) (EC, a key enzyme of tryptophan-niacin metabolism, were assayed. As the result, the urinary excretions of N1-methylnicotinamide (MNA), N1-methyl-2-pyridone-5-carboxamide (2-Py), N1-methyl-4-pyridone-3-carboxamide (4-Py) and their sum (nicotinamide+MNA+2-Py+4-Py) were higher in the D-galN-injected group than in the control group. Hepatic ACMSD activity in the D-galN-injected group was lower than that of the control group. These results suggest that the increase in urinary excretion of nicotinamide and its metabolites after the injection of D-galN is considered to be attributable to a decrease in liver ACMSD activity.

[PubMed - indexed for MEDLINE]
PubMed Commons home

PubMed Commons

How to join PubMed Commons

    Supplemental Content

    Loading ...
    Write to the Help Desk