title: Induction of micronuclei by bleomycin in G0 human lymphocytes: II. Potentiation by radioprotectors.
abstract: Dimethylsulfoxide (DMSO) and WR-1065 are radioprotectors, in that they reduce the effectiveness with which ionizing radiation causes genetic damage. Unlike their protective effects with radiation, these agents potentiate the induction of micronuclei by bleomycin in the cytokinesis-block assay in G0 human lymphocytes. High concentrations of DMSO (1 M) are required to cause potentiation. In contrast, WR-1065 causes dose-dependent potentiation at relatively low concentrations (1.25 to 10 mM). Cytogenetic analysis supports the results from the micronucleus assay, showing higher levels of genetic damage induced by the combination of bleomycin with DMSO or WR-1065 than by bleomycin alone. Possible mechanisms of potentiation are proposed.
authors.affiliation: Department of Biology, College of the Holy Cross, Worcester, Massachusetts 01610.
authors.forename: G R
authors.initials: GR
authors.lastname: Hoffmann
authors.forename: S P
authors.initials: SP
authors.lastname: Colyer
authors.forename: L G
authors.initials: LG
authors.lastname: Littlefield
mesh_terms: D000328:Adult; D001761:Bleomycin / Q000633:toxicity*; D004121:Dimethyl Sulfoxide / Q000494:pharmacology*; D004357:Drug Synergism; D006801:Humans; D008214:Lymphocytes / Q000187:drug effects*; D008297:Male; D008624:Mercaptoethylamines / Q000494:pharmacology*; D015162:Micronucleus Tests; D016012:Poisson Distribution; D011837:Radiation-Protective Agents / Q000494:pharmacology*; D016192:Resting Phase, Cell Cycle
chemical_list: D008624:Mercaptoethylamines; D011837:Radiation-Protective Agents; C020174:N-(2-mercaptoethyl)-1,3-diaminopropane; D001761:Bleomycin; D004121:Dimethyl Sulfoxide