ANTIMONY-TRICHLORIDE INDUCES DNA-DAMAGE AND APOPTOSIS IN MAMMALIAN-CELLS

Antimony compounds are widely used in various manufacturing and semico nducting industries. Previously, it has been shown that antimony trich loride (SbCl3) elevates sister chromatid exchange (SCE) rates in V79 c ells after a 28-h incubation. However, only limited data on its genoto xic effects are available so far. The present results demonstrate that a 4-h exposure to > 50 mu M SbCl3 could induce micronuclei (MN) forma tion in cultured Chinese hamster ovary (CHO-K1) cells, human bronchial epithelial (BES-6) cells and human fibroblasts (HF). The order of sen sitivity to SbCl3 determined by Sulforhodamine B (SRB)-staining surviv al assay is HF > BES-6 cells > CHO-K1 cells, with LD50 values in these cells being approximate to 40, 80 and 180 mu M, respectively. Apoptos is and DNA fragmentation was not found in cells immediately following 4-h SbCl3 treatment. However, DNA fragmentation was detected in CHO-K1 cells after 4-h SbCl3 treatment and a 16 h or more post incubation in fresh medium by 1.5% agarose gel electrophoresis. The delayed apoptos is was also observed under microscopic examination in HF, BES-6 and CH O-K1 cells after similar treatment protocol. In addition, an increase in calcium accumulation appeared in CHO-K1 cells and HF immediately af ter a 4-h SbCl3 treatment, or after a 24-h post incubation in fresh me dium. The present results provide important genotoxic and cytotoxic in formation characterizing the cellular changes induced by short-term Sb C1, exposure in rodent and human cells. (C) 1998 Elsevier Science Irel and Ltd. All rights reserved.