ALTERED PROTEIN-SYNTHESIS IN RAT-KIDNEY CELLS EXPOSED TO SEMICONDUCTOR-MATERIALS

It is thought that the extensive industrial use of arsenic, gallium an d indium, which have applications as the materials for III-V semicondu ctors, will increase human exposure to these compounds in the near fut ure. We have undertaken the development of new biological indicators f or assessing exposure to these elements. Element-specific alterations in protein synthesis patterns were expected to occur following exposur e to arsenic compounds. We examined alterations in protein synthesis i n primary cultures of rat kidney proximal tubule epithelial cells by s odium arsenite, gallium chloride and indium chloride, utilizing two-di mensional gel electrophoresis. After incubation with the chemicals for 20 h, newly synthesized proteins were labeled with [S-35]methionine. A protein with a molecular weight (M(r)) of 30 000 was markedly induce d on exposure to 10 muM arsenite or 300 muM gallium chloride, and synt hesis of proteins with M(r) values of 85 000, 71 000, 65 000, 51 000, 38 000 and 28 000 were also increased by exposure to arsenite and gall ium chloride. No significant changes were observed upon exposure to in dium. Some of these increased proteins could be heat-shock proteins.