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-musc le 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 smo oth-muscle cells than in LLC-PK1 cells; vascular endothelial cells wer e in between vascular smooth-muscle cells and LLC-PK1 cells. The conte nt of reduced glutathione was slightly increased by cadmium in all thr ee 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 th e cells to cadmium cytotoxicity. Vascular smooth-muscle cells may be o ne of the critical target of cadmium toxicity.