Heat shock proteins are induced by cadmium in Drosophila cells

Drosophila cells were treated with increasing concentrations of CdCl2 (10 microM-1 mM). The toxicity of cadmium, as observed by cellular death and the ability of the cells to survive after removal of CdCl2, depended on concentration and duration of treatment. The overall synthesis of protein, measured by incorporation of [35S]methionine, decreased. It fell to 66% of the controls after 24 h of exposition to 50 microM CdCl2 and to 29% after 48 h. We showed that cadmium induced the synthesis of 'heat shock proteins' (hsps), which started after 6 h and was maximal after 24 h of 50-100 microM CdCl2 treatment.