NAD metabolism and induction of tyrosine aminotransferase in the rat.
The relationship between the NAD-metabolism and the induction of the tyrosine aminotransferase was studied. The content of NAD+ + NADH differs markedly from organ to organ. The highest values can be found in the liver. In intact animals tryptophan leads to an increase of NAD in liver and kidney, but not in brain and spleen. Nicotinamide, on the other hand, induces NAD synthesis in all the organs tested. In adrenalectomized animals, however, there is practically no rise of the NAD content after application of tryptophan contrary to the effect of nicotinamide. The enzyme tyrosine aminotransferase can be induced in intact animals by nicotinamide and tryptophan. This effect is much less pronounced in adrenalectomized animals. In adrenalectomized animals the induction of the tyrosine aminotransferase by tryptophan is markedly elevated by caffeine and theophylline. Under these conditions there is a significant increase of the NAD content as well. The tryptophan promoted induction of the tyrosine aminotransferase is influenced by inhibitors of the ADPR-transferase. The data presented give further evidence that the NAD adenoribosylation metabolism is involved in the induction of the tyrosine aminotransferase.
Kröger
H
H
Grätz
R
R
Grahn
H
H
D000315:Adrenalectomy; D000818:Animals; D001921:Brain / Q000201:enzymology; D004790:Enzyme Induction / Q000187:drug effects; D007668:Kidney / Q000201:enzymology; D008099:Liver / Q000201:enzymology; D008297:Male; D009243:NAD / Q000378:metabolism*; D009536:Niacinamide / Q000494:pharmacology; D009928:Organ Specificity; D010084:Oxidation-Reduction; D011239:Prednisolone / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013154:Spleen / Q000201:enzymology; D013806:Theophylline / Q000494:pharmacology; D014444:Tyrosine Transaminase / Q000096:biosynthesis*
D009243:NAD; D009536:Niacinamide; D011239:Prednisolone; D013806:Theophylline; D014444:Tyrosine Transaminase