Influence of leukotriene C4 on aggregation and on malondialdehyde formation of human blood platelets.

The effect of leukotriene C4 on arachidonic acid-induced aggregation and on malondialdehyde formation of human blood platelets was studied. LTC4 (7.2 - 48.3 mumol . 1(-1] inhibited the platelet aggregation in a dose-dependent manner (IC50: 30 mumol . 1(-1]. LTC4 prolonged the lag phase between addition of arachidonic acid and onset of aggregation. Simultaneously the malondialdehyde formation was enhanced by LTC4. By using high doses of LTC4 the malondialdehyde formation was nearly complete at the beginning of the delayed platelet aggregation.