INDUCTION OF METALLOTHIONEIN IN THE REUBER H-35 RAT HEPATOMA-CELL

The feasibility of using the Reuber H-35 rat hepatoma cell (RH-35 cell s) as model for studying metallothionein induction was examined. The R H-35 cells were treated with Cd, a toxic metal which is known to induc e metallothionein. The LC(50) after a 3-h treatment was 70 mu M. The v alue was significantly higher (P < 0.05) if the cells were pre-treated with a sublethal dose of CdCl2 (5 mu M) for 2 days, indicating that p re-treatment with a low dose of Cd can protect against a subsequent hi gher dose of the same metal. Both the mRNA and the gene product metall othionein can be identified in the cells 2 days after treatment with 5 mu M Cd. In addition to Cd, Zn and Cu were also able to induce the ex pression of metallothionein to various degrees. The results indicate t hat the MT gene is present in RH-35 cells and is responsive to treatme nt with various metals. Thus, this cell line can be used as a model to study metallothionein induction.