Inhibitory effect of cisplatin on the enzymatic peroxidation of platelet endogenous arachidonate.

The effect of cisplatin at concentrations of 0.1-33 microM on the enzymatic transformation of arachidonate in pig blood platelets was investigated. Estimation of the level of malonyl dialdehyde (MDA) after stimulation of pig platelets with thrombin (endogenous arachidonate pathway) and exogenous arachidonate served as an indicator of the transformation. MDA concentration was determined by means of a modified method with thiobarbituric acid. The effect of cisplatin on the thrombin-induced formation of MDA in blood platelets was dependent on the time of platelet preincubation with the drug. It was reduced significantly (p < 0.001) after 30 min action of cisplatin on the platelets. In contrast, cisplatin had no effect (p > 0.05) on the arachidonate pathway dependent on the activity of thromboxane synthase.