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.