Syrian hamster embryo cells metabolic activation

Acetamide was mutagenic in Escherichia coli and Salmonella typhimurium-, this effect was independent of dose. Acetamide produced morphological transformation in Syrian hamster embryo cells in the absence of metabolic activation. However, acetamide did not induce reversions in several Salmonella typhimurium strains. ... 

In one of two studies, di(2-ethylhexyl) phthalate induced a small increase in sister chromatid exchange frequencies in Chinese hamster ovary cells cultured without but not with exogenous metabolic activation. In other studies conducted only without metabolic activation, it caused no increase in sister chromatid exchanges in either Chinese hamster Don cells or rat liver RL4 cells. Di(2-ethylhexyl) phthalate did not induce micronuclei in Chinese hamster ovary cells or in cultured rat hepatocytes, whereas the induction of micronuclei by di(2-ethylhexyl) phthalate in Syrian hamster embryo cells has been reported. 

Chromosomal aberrations were not induced by di(2-ethylhexyl) phthalate in any of eight studies in various types of cultured cells in the absence of metabolic activation. Only three of these studies for chromosomal aberrations included an exogenous metabolic activation system. Of these, one, using Syrian hamster embryo cells, found an increase in aberration frequency. Weak effects were detected for the induction of aneuploidy and mitotic division aberrations in Chinese hamster lung cells. 

RLV/Fischer rat assay without the addition of an exogenous metabolic activation system. In a single study, mouse JB6 epidermal cells were transformed by di(2-ethyl-hexyl) phthalate without activation and in one of two studies a weak response was reported in the CSHIOT A cell transformation assay with di(2-ethylhexyl) phthalate in either the absence or presence of exogenous metabolic activation. BALB/c-3T3 cells were not transformed by di(2-ethylhexyl) phthalate with or without metabolic activation. Di(2-ethylhexyl) phthalate inhibited gap-junctional intercellular communication in Chinese hamster V79 cells in six of seven studies, but not in one study of liver cells of cynomolgus monkeys in vivo. Di(2-ethylhexyl) phthalate treatment of Syrian hamster embryo cells in a two-stage exposure with 12-O-tetradecanoylphorbol 13-acetate resulted in superinduction of ornithine decarboxylase, an early event in morphological transformation no effect was seen after a one-stage treatment with di(2-ethylhexyl) phthalate alone. 

Trichloroethane did not induce unscheduled DNA synthesis in rat primary hepatocytes. It showed inconclusive evidence of gene mutation at the tk locus in mouse lymphoma L5178Y cells in the presence of an exogenous metabolic activation system. Results for induction of sister chromatid exchanges were also inconclusive. 1,1,1-Trichloroethane increased the frequency of chromosomal aberrations in Chinese hamster ovary cell cultures and induced morphological transformation in BALB/c 3T3 and in Fischer rat and virally-enhanced Syrian hamster embryo cells in vitro. 

Cultured cells (from human peripheral blood lymphocytes or from Syrian hamster embryo (SHE)) or cell lines (CHO, V79, CHL/IU, L5178 Y) are exposed to the test substances both with and without an exogenous source of metabolic activation unless primary cells with metabolizing capability are used. After exposure to the test substance, cell cultures are grown for a sufficient period to... 

DNT, 3,4-DNT, 2,6-DNT) and technical grade DNT were unable to induce morphological transformation of Syrian hamster embryo (SHE) cells in culture, suggesting that some important activation step was missing in SHE cells [45], An example showing that some primary cells may have the ability to metabolize... 

Feeder-layer experiments depend on the ability of a chemical activated by an irradiated feeder layer of metabolizing cells to induce SCEs in exponentially dividing tester cells. Syrian hamster secondary embryo cultures that have been shown to metabolize various carcinogenic polycyclic aromatic hydrocarbonsare used as the feeder layer, and Chinese hamster V79 cells are the tester cells. The irradiated embryo culture cells are mixed with the V79 cells before being plated in petri dishes. Chemicals are added 24 hr later with BrdUrd, and the cells are fixed after an additional 24 hr. Positive results are obtained with benzo[a]pyrene, 3-methylcholanthrene, and dimethylben-zanthracene, none of which induces SCEs in the absence of the feeder layer. 

Cells Chinese hamster CHO(SCl), CHO, V79, V79-4, DON, Cl-1, D-6 Syrian hamster BHK mouse 3T3, ME (mouse embryo primary cells) human HPBL (human peripheral blood lymphocytes), NHF (normal human fibroblasts), XP (xeroderma pigmentosum), FA (Fanconi s anemia), BS (Bloom s syndrome) Muntjac. Activation In experiments in which poor metabolizing ability of cells is augmented by an activation system S9 (Ames S-9 Mix), FL (irradiated feeder layer of metabolizing cells). 

---