title: Chromosomal aberration, mutation and morphological transformation of Syrian hamster embryonic cells after exposure to methylnitrosocyanamide.
abstract: Hamster embryonic fibroblasts were treated directly with various concentrations of methylnitrosocyanamide (MNC), a nitrosated product of methylguanidine (MG) or N-methyl-N'-nitro-N-nitrosoguanidine (MNNG). Then they were examined for chromosomal aberrations, morphological transformation and mutations resistant to 8-azaguanine (8AG) and 6-thioguanine (6TG). Direct treatment with 2 to 10 X 10(-6) M MNC caused a marked, dose-dependent appearance of 8AG- and 6TG-resistant mutations. The ability of MNC to induce mutations was similar to that of MNNG. Cultured embryonic fibroblasts in metaphase plates also showed a marked dose-dependent increase in chromosomal aberrations within 24 h after direct treatment with MNC or MNNG. Moreover, MNC and MNNG caused similar rates of morphological transformation.
mesh_terms: D000818:Animals; D001375:Azaguanine / Q000494:pharmacology; D002460:Cell Line; D002471:Cell Transformation, Neoplastic; D002869:Chromosome Aberrations; D002875:Chromosomes / Q000187:drug effects; D006224:Cricetinae; D004305:Dose-Response Relationship, Drug; D004351:Drug Resistance; D006146:Guanidines / Q000494:pharmacology*; D008647:Mesocricetus; D008760:Methylguanidine / Q000494:pharmacology*; D008769:Methylnitronitrosoguanidine / Q000494:pharmacology; D009154:Mutation; D009602:Nitrosamines / Q000494:pharmacology*; D013866:Thioguanine / Q000494:pharmacology
chemical_list: D006146:Guanidines; D009602:Nitrosamines; D008769:Methylnitronitrosoguanidine; C011927:methylnitrosocyanamide; D008760:Methylguanidine; D013866:Thioguanine; D001375:Azaguanine