Key Points
- To identify and determine the molecular structure and biological activity of the unstable intermediate thromboxane A2 generated during prostaglandin endoperoxide metabolism.
- Incubated washed human platelets with arachidonic acid or prostaglandin G2 (PGG2) for 30 seconds.
- Trapped the intermediate using methanol, ethanol, sodium azide, and CH3O2H, analyzing structures via isotopic labeling with 18O2 and [2H8]arachidonic acid.
- Assayed platelet aggregation, [14C]serotonin release, and smooth-muscle contractile activity corresponding to rabbit aorta contracting substance (RCS).
- Identified thromboxane A2 as an unstable intermediate with a half-life of 32 ± 2 seconds at 37 °C, possessing an oxane ring and an oxetane structure.
- Demonstrated that thromboxane A2 potently induces irreversible platelet aggregation and stimulates [14C]serotonin release.
- Showed that thromboxane A2 represents the major, highly unstable component of rabbit aorta contracting substance (RCS) generated in platelets and guinea pig lungs.
Structured PICO
PPopulationWashed human platelets and guinea pig lung
IInterventionIncubation with arachidonic acid or prostaglandin G2
OOutcomeDetection and structural characterization of thromboxane A2surrogate
This landmark basic science study identified and characterized thromboxane A2, a potent inducer of platelet aggregation derived from prostaglandin endoperoxides.