Indium chloride-induced micronuclei in in vivo and in vitro experimental systems.

OBJECTIVES The aim of this study was to investigate the genotoxic effects of indium trichloride (InCl(3)·4H(2)O; InCl(3)) using the in vivo bone marrow micronucleus test and the in vitro CHL/IU cell micronucleus test. METHOD BALB/c mice were administered a single intraperitoneal (i.p.) injection of InCl (3) at a dose 0.625, 1.25, 2.5, 5, or 10 mg/kg b.w. The frequency of micronuclei, the ratio of polychromatic erythrocytes to normochromatic erythrocytes (P/N ratio) and body weight gain were determined 24 h after administration of the InCl(3). In the in vitro micronucleus test, CHL/IU cells were treated continuously for 24, 48, or 72 h in the absence of S9mix (the continuous treatment method) and/or for 6 h with or without S9 mix followed by an 18, 42 or 66 h recovery time (the short time treatment method). The frequency of micronuclei was determined at the end of each culture period. RESULTS The frequency of micronuclei induced by InCl(3) increased in the in vivo erythroblast-erythrocyte micronucleus test using BALB/c mice at doses of 2.5 and 5 mg/kg b.w. The P/N ratio, a marker of bone marrow toxicity, decreased significantly following the injection of InCl(3). Body weight gain was also inhibited by InCl(3). InCl(3) induced micronuclei in the CHL/IU cell micronucleus test in both the continuous treatment method and the short time treatment method, both with and without S9mix. CONCLUSIONS These results suggest that InCl(3) has a genotoxic effect on mammalian cells both in vivo and in vitro.