Cyclooxygenase and lipoxygenase metabolites during platelet aggregation: Quantitative measurement by negative ion chemical ionization — gas chromatography / mass spectrometry

Abstract

This study was aimed at investigating systemetically the aggregation of human gel filtered platelets induced by various physiological stimuli such as thrombin (0.25 U/ml), collagen (2 μg/ml), a mixture of thrombin and collagen, and ADP (2–5 μM). For quantitative measurement of TXB2, PGF2a and 12-HETE, negative ion chemical ionization - gas chromatography/mass spectrometry using stable isotope dilution was applied. Stimulation by thrombin, collagen and the combined agonists resulted in an increase of TXB2 (up to 54 ng/1 × 10⁸ platelets) and 12-HETE (up to 44 ng/1 × 10⁸ platelets) during platelet aggregation. The simulation with ADP showed only little increase of these metabolites and this only during the second wave of aggregation. Very little amounts of PGF2α were produced during thrombin stimulated aggregation.