Sensitive response of cultured vascular smooth-muscle cells to cadmium cytotoxicity: comparison with cultured vascular endothelial cells and kidney epithelial LLC-PK1 cells.

Response to cadmium cytotoxicity of cultured bovine aortic smooth-muscle cells was compared with that of cultured bovine aortic endothelial cells and porcine kidney epithelial LLC-PK1 cells. The cell damage was evaluated by morphology and the lactate dehydrogenase leakage assay. It was found that vascular smooth-muscle cells are markedly sensitive to cadmium cytotoxicity. The accumulation of intracellular cadmium was much higher but that of metallothionein was much less in vascular smooth-muscle cells than in LLC-PK1 cells; vascular endothelial cells were in between vascular smooth-muscle cells and LLC-PK1 cells. The content of reduced glutathione was slightly increased by cadmium in all three cell types. The present data suggest that a much lower inducibility of metallothionein with a high accumulation of intracellular cadmium in vascular smooth-muscle cells resulted in a marked sensitivity of the cells to cadmium cytotoxicity. Vascular smooth-muscle cells may be one of the critical target of cadmium toxicity.