Simultaneous determination of 6-oxo-prosta-glandin F1α and 2,3-dinor-6-oxo-prostaglandin F1α in biological fluids by stable isotope dilution and negative ion chemical ionization mass spectrometry

Abstract

A stable isotope dilution assay for the simultaneous determination of two metabolites of prostacyclin (1), 6-oxo-prostaglandin F1 alpha (2a) and 2,3-dinor-6-oxo-prostaglandin F1 alpha (3a), in human seminal fluid and human urine is described. A new chemical total synthesis of deuterated internal standard, 18,18,19,19-(2H4)-2,3-dinor-6-oxo-PGF1 alpha (3b), is presented and enables specific and sensitive quantification based on negative ion chemical ionization mass spectrometry. 2a and 3a were analysed as their methoxime pentafluorobenzyl ester tris(trimethylsilyl) ether derivatives in the selected ion monitoring mode registrating the [M-181]- fragments with a detection limit for both prostanoids of 10 pg per injection. The two metabolites occur in human seminal fluid in very low concentrations (2a: 2.8 ng ml-1; 3a: 1.7 ng ml-1) and cannot contribute significantly to the urinary metabolite levels which are in the range of 108-265 ng/24 h for 3a and 124-574 ng/24 h for 2a.

Determination of Prostacyclin in Plasma through a Bioluminescent Immunoassay for 6-Keto-prostaglandin F1α: Implication of Dosage in Patients with Primary Pulmonary Hypertension

“…Various types of detection methods have been reported in the literature for prostacyclin using its stable hydrolysis product, 6-keto-PGF 1 α , as a measure of prostacyclin levels. For example, the methods include radioimmunoassays, enzyme immunoassays, and detection using gas liquid chromatography/mass spectrometry (GLC/MS) or gas chromatography-selective ion monitoring (GC-SIM). ,, Radioimmunoassay is a highly sensitive method, but it has the disadvantages associated with the use of radioactivity. Moreover, all the immunoassays or chromatographic techniques reported for 6-keto-PGF 1 α require extraction of 6-keto-PGF 1 α from plasma or serum samples, making the process laborious and time-consuming. ,, We have developed a sensitive bioluminescent immunoassay for 6-keto-PGF 1 α in which the plasma samples can be analyzed directly in the assay without requiring the extraction of 6-keto-PGF 1 α from plasma.…”

Simultaneous Solid Phase Extraction, Derivatization, and Gas Chromatographic Mass Spectrometric Quantification of Thromboxane and Prostacyclin Metabolites, Prostaglandins, and Isoprostanes in Urine

“…To understand the role of the functionally diverse arachidonic acid products in these conditions requires the sensitive and specific detection of nanomolar levels of structurally closely related metabolites in complex biological matrices. GC/MS methods are best suited and have been described for the index metabolites of prostacyclin − and thromboxane − formation, classical prostaglandins, and isoprostanes. − These methods usually require a separate, extensive sample workup for a single prostaglandin metabolite. A few methods have been tried to accomplish the analysis of more than one prostanoid or their metabolites, − but these usually include time-consuming chromatographic steps requiring the splitting of the sample or the use of tandem mass spectrometry (GC/MS/MS).…”

Mass spectrometry/mass spectrometry of prostaglandins: Daughter ion spectra of derivatized and isotope-labeled E and D prostanoids

“…prostaglandins (E and D type) and their deuteriated analogues in greater detail. The objectives of this study are (1) to define more thoroughly the MS/MS fragmentation of E and D prostanoids at high energies (6 keV in the laboratory reference frame) under unimolecular and collisionally activated dissociation (CAD) conditions, (2) to examine the choices available for parent ion to daughter ion reactions, for simplified SRMbased assays of PG's in biological fluids, (3) to begin to investigate how these choices affect the selectivity of SRM-based assays, and (4) ultimately to develop a rationale for choosing which reaction to monitor, given the myriad of possible reactions in any given system. EXPERIMENTAL SECTION Materials and Methods.…”