Formulation: A solution in ethanol (1 μg/ml each compound)
Shelf life (days): 1825
Notes: This mixture contains a collection of metabolites of the major vasoactive eicosanoids, prostaglandin I2 (PGI2; Item No. 18220) and thromboxane A2 (TXA2), as well as of several oxylipins postulated to regulate vasoconstriction. The mixture is supplied in an amber ampule in which the headspace has been purged with argon to prevent lipid oxidation. This product has been designed for direct use in LC-MS applications. The solution may be serially diluted for preparation of calibrators and QC standards and/or used directly as a system suitability standard or tuning standard. After opening, we recommend that the mixture be transferred immediately to a 1 ml glass screw cap vial, to prevent solvent evaporation, and stored at -20°C. The mixture should be discarded after multiple freeze/thaw cycles.Whereas PGI2 is a potent vasodilator and inhibitor of human platelet aggregation, TXA2 causes irreversible platelet aggregation and contraction of vascular and bronchial smooth muscle. Because both are rapidly metabolized, their urinary metabolites (11-dehydro TXB2 (Item No. 19500), 2,3-dinor TXB2 (Item No. 19050), 11-dehydro-2,3-dinor TXB2 (Item No. 19510), and 2,3-dinor-6-keto PGF1α (Item No. 15120), serve as useful markers for their synthesis.{264,6109,7635,1410,438,410} The diol metabolites of various epoxyeicosatrienoic acids (EETs) have been used to document the oxylipins involved in vasoconstriction and hypertension.{7827,1116,3962}