Characteristics of Platelet Factor 3 Release during ADP-Induced Aggregation

Summary

Comparison of serotonin release with PF 3 release during ADP-induced aggregation revealed that the two release reactions are entirely different processes. Serotonin release was found to occur at temperature above 33° C; the optimal temperature was 43° C and maximum release occurred 3 min after addition of ADP. PF 3 release was slow and linear with time occurring both at 37° C and 20° C but it was more prolonged at 20° C. Serotonin release as well as PF 3 release were neglibible in reversible aggregation. The influence of surface contact and stirring speed indicated the significance of mechanical trauma in PF 3 release. In the discussion, mention is made of the possibility that the peripheral balloon-shaped platelet protrusions are subject to membrane changes and thus lead to PF 3 release.

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