Induction of cancers in the intestine, liver and various other organs of rats by feeding mutagens from glutamic acid pyrolysate.

The mutagenic compounds 2-amino-6-methyldipyrido[1,2-alpha:3',2'-d]imidazole (Glu-P-1) and 2- aminodipyrido [1,2-alpha: 3',2'-d]imidazole (Glu-P-2), which were isolated from a glutamic acid pyrolysate and are potent carcinogens in the liver and brown adipose tissue of mice, were found to be multipotent carcinogens in rats. These compounds were each given to F344 rats of both sexes at a concentration of 500 ppm in pellet diet for up to 24 months. Glu-P-1 induced tumors in the colon, small intestine, liver, Zymbal gland, clitoral gland and brain.

Genetic control of susceptibility of rats to gastric carcinoma.

Genetic control of the induction of gastric tumors by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was studied in susceptible ACI rats, resistant Buffalo rats, and their F1 and F2 offspring. Both sexes of all strains, initially 7 to 9 weeks old, were given MNNG at a concentration of 83 micrograms/ml in their drinking water for 32 weeks and were sacrificed at experimental Week 72. The incidence of gastric adenocarcinoma in ACI rats was 80% in males and 47% in females; in Buffalo rats, the incidence was 18% in males and 0% in females.

[Genetic factors in gastric carcinogenesis].

Genetic control of susceptibility of rats to gastro-carcinogenesis by N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) was studied in susceptible ACI strain rats, resistant Buffalo strain rats, and their F1 and F2 offsprings. Rats were given MNNG at a concentration of 83 micrograms/ml in drinking water for 32 weeks and sacrificed on week 72. The incidence of gastric adenocarcinomas in F1 was as low as that in Buffalo rats.

Genetic study of host factors in gastrocarcinogenesis in rats.

The effects of genetic factors on gastrocarcinogenesis in rats were studied by giving 83 micrograms/ml of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in the drinking-water to ACI strain rats, Buffalo strain rats, and their F1 hybrid rats for eight months. Animals were sacrificed on the 505th experimental day and examined histologically. The incidences of gastric carcinoma were as follows (no.

Genetic control of sensitivity of rats to gastrocarcinogenesis by N-methyl-N'-nitro-N-nitrosoguanidine.

The administration of N-methyl-N'-nitro-N-nitrosoguanidine (MNNG) in drinking water induces tumours, mainly adenocarcinomas in the glandular stomach of rats. The sensitivities of different strains of rats to gastrocarcinogenesis induced by MNNG vary: Wistar and ACI strains are sensitive, whereas the Buffalo strain is resistant. Genetic analyses were made on the induction of gastric tumous by MNNG in the ACI and Buffalo strains and their F1 and F2 hybrids.

Carcinogenicity test of quercetin and rutin in golden hamsters by oral administration.

Quercetin and its glycoside, rutin were tested for carcinogenicity in non-inbred golden hamsters of both sexes. In Experiment I, 10% quercetin, 10% rutin, or control diet was given to animals for 735 days. In this experiment, tumors appeared mainly in the forestomach, but the incidence was not statistically different among the three groups.

Carcinogenicity in rats of the mutagenic compounds 1-nitropyrene and 3-nitrofluoranthene.

1-Nitropyrene and 3-nitrofluoranthene are present in diesel exhaust, in pollutants in air, and were also present in certain xerographic toners and copies. Their carcinogenicities were studied in male F344/DuCrj rats by subcutaneous injection. Sarcomas, mainly malignant fibrous histiocytomas at the site of injection were induced in 8 to 17 (47%) rats by 1-nitropyrene and in 4 of 10 (40%) rats by 3-nitrofluoranthene.

Liver cancer and precancerous changes in rats induced by the basic fraction of tryptophan pyrolysate.

The basic fraction of a tryptophan pyrolysate (Trp-P-BF) was given orally to Wistar rats for about 2 years. In Experiment I, 5 male rats each were given 0.2, 0.

Carcinogenicity in mice of mutagenic compounds from a tryptophan pyrolyzate.

The compounds 3-amino-1,4-dimethyl-5H-pyrido[4,3-b]indole and 3-amino-1-methyl-5H-pyrido[4,3-b]indole, which are potent mutagens in a tryptophan pyrolyzate, ar hepatic carcinogens when given orally to mice at concentrations of 200 parts per million in a pellet diet. Female mice showed higher susceptibilities to both compounds than male mice.