Unsaturated platelet-activating factor: influence on aggregation, serotonin release and thromboxane synthesis of human thrombocytes.

Unsaturated platelet-activating factor (paf-acether) aggregated thrombocytes of healthy male volunteers like saturated paf-acether. Unsaturated paf-acether released serotonin in the presence of imipramine. Within one minute the release increased depending on the concentrations of unsaturated paf-acether up to 45% of the serotonin. Human thrombocytes synthesized only a small amount of thromboxane B2 (TXB2) after aggregation induced by unsaturated paf-acether. Unsaturated paf-acether prevented the binding of radiolabelled saturated paf-acether to intact washed thrombocytes in the same extent as saturated paf-acether.