1 The ability of dextran sulphate to protect cultured porcine arterial endothelial cells injured by addition of xanthine and xanthine oxidase (X/XO) or hydrogen peroxide to cell medium was examined using a variety of drug preparations. Cell damage was assessed by determining cell viability (by trypan blue exclusion) and release of lactate dehydrogenase into the medium.
2 Dextran sulphates of average molecular weight (Mr) 5000, 8000 (hydrogenated or unhydrogenated) at 0.05, 0.5, 5 and 50 μg ml-1 medium, added 24 h prior to X/XO, protected cells, whereas dextran sulphate Mr 500,000 was protective only at 0.5 μg ml-1.
3 None of the dextran sulphates used showed any toxic effect on cells in concentrations up to 500 μg ml-1 medium.
4 When the duration of pretreatment with dextran sulphate Mr 8000 was varied, 6 h was required for a protective effect on cells damaged by X/XO, which was enhanced with durations of 16 and 24 h.
5 Dextran sulphates had a similar protective effect on cells damaged by hydrogen peroxide.
6 This study suggests that dextran sulphates may prevent conditions resulting from free radical injury.