Platelet release of β-thromboglobulin and platelet factor 4 and serotonin in plasma samples

Objectives: Platelet release of α granule-derived CXC chemokines and dense granule-derived serotonin in plasma samples was evaluated. Methods: Concentrations of the CXC chemokines β-TG and PF4 were assayed by an enzyme immunoassay; serotonin was measured by an HPLC method. Results: β-TG and PF4 were more easily released than serotonin by in vitro procedures. Use of the anti-platelet cocktail CTAD and preservation of the samples at 4°C were necessary to accurately measure β-TG and PF4, but not serotonin. Conclusions: Assaying serotonin may be useful for assessing platelet activation in vivo as a laboratory test because of facile preparation of plasma samples.