The influence of citrate on platelet aggregation and malondialdehyde production

3 commonly used parameters for platelet aggregability were tested for their dependence on citrate concentrations. Relatively minor changes in citrate concentrations markedly influenced ADP threshold values for secondary aggregation. Collagen induced platelet malondialdehyde (MDA) production was reduced by increasing the citrate level. This effect was still present in plasma which was also anticoagulated with EDTA. Thrombin induced MDA production was considerably higher in EDTA than in citrate plasma. Citrate appears to inhibit aggregation as well as MDA synthesis. The latter effect does not seem to be solely caused by the effect of citrate on ionized calcium levels.