Antimutagenic action of cobaltous chloride on radiation-induced mutations in cultured Chinese hamster cells

Abstract

The effects of cobaltous chloride on 8-azaguanine (8AG)-resistant mutations induced by γ-rays or ultraviolet (UV) light in cultured Chinese hamster V79 cells were examined. Cobaltous chloride alone had no significant effects on survival and mutations of V79 cells at concentrations less than 1 × 10 −5 M. Cobaltous chloride at a concentration of 3 × 10 −6 M had a marked effect in reducing 8AG-resistant mutations induced by γ-rays of 2–6 Gy, when cells were incubated for 6–7 days in the presence of cobaltous chloride after γ-ray irradiation (posttreatment). The pretreatment of cells with cobaltous chloride for 6 days before γ-ray irradiation reduced 8AG-resistant mutations induced by γ-rays. Pre- or post-treatment with cobaltous chloride had no such effect on UV-induced mutations, however. The difference in responsiveness to cobaltous chloride between bacterial and mammalian cell systems is discussed.