Detail of "53-96-3"

Reference

The resistance of putative premalignant liver cell populations, hyperplastic nodules, to the acute cytotoxic effects of some hepatocarcinogens

The resistance of putative premalignant liver cell populations, hyperplastic nodules, to the acute cytotoxic effects of some hepatocarcinogens. Farber, Emmanuel; Parker, Sally; Gruenstein, Margot (Sch. Med., Temple Univ., Philadelphia, Pa., USA). Cancer Res., 36(11, Pt. 1), 3879-87 (English) 1976. CODEN: CNREA8. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) Section cross-reference(s): 18 The hypothesis that liver carcinogenesis may have as an important facet the early selection of carcinogen-resistant cells was tested in animals in which putative premalignant hepatocyte populations, hyperplastic nodules, were induced by 2-acetylaminofluorene (I) [53-96-3] or by ethionine [13073-35-3]. Hyperplastic nodules were obsd. to be resistant to the acute necorgenic effects of 2 hepatotoxins, CCl4 [56-23-5] and dimethylnitrosamine [62-75-9], under conditions in which liver cell necrosis occurred in the liver surrounding the nodules. In addn. 62-75-9 and 13073-35-3 are also in the experiment., although dimethylnitrosamine-methyl-3H was taken up to an equal degree in nodules and normal liver, the interactions with DNA, RNA, and protein in hyperplastic nodules were found to be about 50% less than in control liver. Hyperplastic nodules showed a marked decrease in uptake of I-9-14C, a finding that could account for the large decrease in labeling of DNA, RNA, and protein by I-9-14C obsd. in the nodules. The results are consistent with and support the hypothesis that new hepatocyte populations that appear prior to cancer, during liver carcinogenesis, have as an important biol. property a resistance to the cytotoxic effect of hepatocarcinogens. The basis for this resistance might be a decrease in uptake and/or a redn. in the level of activation of carcinogens. .

Absorption and protein binding of N-2-fluorenylacetamide and its metabolites in the bladder of the rabbit

Absorption and protein binding of N-2-fluorenylacetamide and its metabolites in the bladder of the rabbit. Hopp, Martin L.; Matsumoto, Michio; Lee, Chung; Oyasu, Ryoichi (Med. Sch., Northwest. Univ., Chicago, Ill., USA). J. Natl. Cancer Inst., 58(2), 281-5 (English) 1977. CODEN: JNCIAM. DOCUMENT TYPE: Journal CA Section: 4 (Toxicology) To assess the reactivity of a bladder carcinogen, the absorption by the rabbit (male New Zealand White) bladder mucosa of N-2-acetylaminofluorene (I) [53-96-3], N-hydroxy-2-acetylaminofluorene (N-OH-AAF) [53-95-2], and AAF N-O-glucuronide (N-OGl-AAF) [2495-54-7], as well as binding to the protein and RNA of bladder mucosa, was measured in vivo and in vitro. Mucosal pieces incubated for 3 h in medium contg. a carcinogen demonstrated that the fluorene nucleus of both I and N-OH-AAF bound equally with cellular proteins, while N-OGl-AAF binding was lower. In the presence of an excess of .beta.-glucuronidase [9001-45-0], however, N-OGl-AAF showed binding equivalent to its metabolic precursor. After a 3-h instillation into the bladder lumen of radioactive carcinogens suspended in urine in vivo, transmural absorption of I and N-OH-AAF (90%) was substantial, while N-OGl-AAF was absorbed less (55%). 53-95-2 and 2495-54-7 which are cas registry numbers of substances are two of reagents here. The renal excretion during this period varied from 18 to 52% of the instilled radioactivity. There was little reactivity of these carcinogens with the mucosal RNA, both in vivo and in vitro. The metab. of N-OH-AAF and N-OGl-AAF was such, both in vitro and in vivo, that the acetyl group was not included in the final protein-carcinogen complex in what appeared to be an enzyme reaction. .