title: Induction of chromosome aberrations and sister-chromatid exchanges in CHO-K1 cells by o-phenylphenol.
abstract: o-Phenylphenol (OPP), is used in Japan as a fungicide in food additives for citrus fruits. The induction of chromosome aberrations and sister-chromatid exchanges (SCEs) by OPP in cultured Chinese hamster ovary (CHO-K1) cells was studied. Cells were exposed to various concentrations of OPP ranging from 50 to 175 micrograms/ml for 3 h, and further incubated for 27 and 42 h. These incubation periods are almost equal to 2 and 3 cell cycles. SCEs and chromosome aberrations were induced by OPP at concentrations of 100, 125 and 150 micrograms/ml after the incubation for 27 h. For chromosome aberrations, chromatid breaks and exchanges there was a dose-dependent increase. Diplochromosomes due to endoreduplication were also caused by the same concentrations of OPP in a dose-dependent manner. After incubation for 42 h, chromosome aberrations were also increased by OPP at concentrations of 100 and 125 micrograms/ml, but the frequencies of SCEs were not significantly different from those of the control. These results suggest that OPP has a cytogenetic toxicity, and that the DNA damage resulting in SCEs induced by OPP is relatively short-lived and can be repaired during the longer incubation time.
mesh_terms: D000818:Animals; D001713:Biphenyl Compounds / Q000633:toxicity*; D002460:Cell Line; D002869:Chromosome Aberrations; D006224:Cricetinae; D003412:Cricetulus; D004305:Dose-Response Relationship, Drug; D005260:Female; D008769:Methylnitronitrosoguanidine / Q000633:toxicity; D010053:Ovary; D012854:Sister Chromatid Exchange / Q000187:drug effects*; D013997:Time Factors
chemical_list: D001713:Biphenyl Compounds; D008769:Methylnitronitrosoguanidine; C004369:2-phenylphenol