In vitro effects of cadmium on two different animal cell models

The aim of this study was to assess comparatively the effects of cadmium on two different in vitro cell models, a cell line derived from proximal tubu le renal cells (LLC-PK1) and haemocytes or blood cells of mussels (Mytilus galloprovincialis). Cells were seeded in 96-well microplates and exposed in vitro to different concentrations of cadmium (CdCl2) ranging from 10 to 20 00 muM for haemocytes and from 1 to 100 muM for LLC-PK1 cells, added to the culture medium. After 24 h of exposure, different assays were performed on haemocytes: neutral red uptake, phagocytosis of neutral red-stained zymosa n, XTT assay, activity of lysosomal acid phosphatase and demonstration of t he actin cytoskeleton using TRITC-labeled phalloidin. Cell viability expres sed as LC50 was 750 gm when using the neutral red assay and 400 muM with th e XTT assay. The phagocytic ability and the activity of acid phosphatase in creased significantly in cells treated with Cd in a non dose-dependent mann er. Doses of Cd above 100 muM caused disruption of the actin cytoskeleton. In LLC-PK1 cells, cell viability expressed as LC50 was found to be around 4 0 muM when using the neutral red assay and 50-60 muM with MTT and LDH assay s, respectively. These results show that mussel haemocytes are in general m ore resistant to Cd exposure than LLC-PK1 cells. Furthermore, Cd appears to stimulate phagocytic and lysosomal activities in haemocytes in vitro. (C) 2001 Elsevier Science Ltd. All rights reserved.