Production of thromboxane and prostaglandins in human blood in the presence of thromboxane synthase inhibitors: a comparison of RIA and GC/MS determinations.
The radioimmunological determination (RIA) of primary prostaglandins (PGs) in serum and plasma was evaluated with gas chromatography/mass spectrometry (GC/MS). Human blood was stimulated in vitro in the presence or absence of the specific thromboxane synthase inhibitor ridogrel. TxB2, 6-keto-PGF1 alpha, PGE2, PGD2 and PGF2 alpha were determined with RIA and GC/MS on the same samples. For GC/MS analysis, prostanoids were extracted and derivatized to their methoximepentafluorobenzyl-esters-trimethylsilyl-ethers. An excellent correlation was observed between levels of all eicosanoids determined by RIA or GC/MS (r = 0.996-0.999) when plasma was spiked with known amounts of PGs and TxB2 (2-500 ng/ml). In stimulated blood, with or without inhibition of thromboxane synthase, the correlation between RIA and GC/MS values remained good, except for 6-keto-PGF1 alpha. RIA largely overestimated the levels of 6-keto-PGF1 alpha and no significant correlation was found with levels detected by GC/MS. The results demonstrate the importance of corroborating the reliability of RIA with GC/MS.
Weber
C
C
Janssen Research Foundation, Neuss, Germany.
Beetens
J R
JR
Van de Wiele
R
R
Höller
M
M
De Clerck
F
F
D015121:6-Ketoprostaglandin F1 alpha / Q000032:analysis; D003094:Collagen / Q000494:pharmacology; D008401:Gas Chromatography-Mass Spectrometry; D006801:Humans; D010421:Pentanoic Acids / Q000494:pharmacology; D011453:Prostaglandins / Q000096:biosynthesis / Q000097:blood*; D011725:Pyridines / Q000494:pharmacology; D011863:Radioimmunoassay; D013917:Thrombin / Q000494:pharmacology; D013929:Thromboxane B2 / Q000096:biosynthesis / Q000097:blood*; D013930:Thromboxane-A Synthase / Q000037:antagonists & inhibitors*
D010421:Pentanoic Acids; D011453:Prostaglandins; D011725:Pyridines; D013929:Thromboxane B2; D015121:6-Ketoprostaglandin F1 alpha; D003094:Collagen; D013917:Thrombin; D013930:Thromboxane-A Synthase; C060219:ridogrel