Ribonuclease activity of ribonucleoprotein particles isolated from livers of rats fed 4-dimethylaminoazobenzene, primary liver tumors, and Novikoff hepatoma.

The effect of feeding 3'-methyl-4-dimethylaminoazobenzene on tryptophan metabolism of rats.

Liver tryptophan pyrrolase and kynureninase activity decreased when rats were fed the hepatic carcinogen 3'-methyl-4-dimethylaminoazobenzene, whereas li ver kynurenine transaminase activity did not differ significantly from that of the controls. Liver tumors induced by this aminoazo dye had very low kynurenine transaminase activity and no detectable tryptophan pyrrolase or kynureninase activity...

The histochemical localization of alkaline phosphatase during carcinogenesis in rats fed p-dimethylaminoazobenzene.

Greenstein in 1942 found a high content of alka line phosphatase in transplanted rat hepatoma 31 (3). This tumor arose originally in the liver of a male Osborne-Mendel rat and was induced by the basal diet of White and Jackson (16) containing 0.06 percent />-diinethylaniinoazobenzene (DAB) with intermittent addition of 0.5 per cent cystine and 0.5 per cent methionine (17). The enzyme ac tivity ...

Profiles of total ribonucleoprotein particles from normal rat liver, primary liver tumors, and Novikoff hepatoma.

The effect of feeding 2-acetylaminofluorene on ribonuclease activity in the serum and liver mitochondria of rats.

Prior to the present study, several investiga tions of ribonuclease (RNase) activity in tumor tissue and in precancerous and cancerous liver have been reported. In the earliest work, Greenstein and co-workers (5) studied RNase in normal and neoplastic tissues. Compared with controls, little change of activity was reported in rat hepatoma, but higher activities were observed in mouse hepatoma th...

Correlation of the Level of Hepatic Riboflavin with the Appearance of Liver Tumors in Rats Fed Aminoazo Dyes

The livers of rats fed 10 diets previously found to inhibit or accelerate the induction of tumors by 4-dimethylaminoazobenzene were analyzed for riboflavin, biotin, and vitamin B(6) after 6 and 19 weeks on the diets. Those fed diets accelerating tumor induction had average hepatic riboflavin levels of 9 to 11 microg. per gm. The livers of the control and protected rats averaged 14 and 15 to 19 ...