thromboxane-b2 and Alveolitis--Extrinsic-Allergic

BN50739 is a new and potent PAF antagonist. In this experiment, we have further confirmed that it is a selective PAF antagonist by means of rabbit platelet aggregating test. And also, when BN50739 was applied, in the concentration of 10 uM, to the isolated lung of guinea pig sensitized by ovalbumin, we observed that the amount of histamine and thromboxane A2 released was a little less (about 19.0% and 19.2%, respectively) than that of controls (P < 0.05). Whereas, the ratio of PGI2/TxA2 was increased by 17.6% comparing to that in control group (P < 0.05). But the level of LTC4 remained unchanged regardless of the presence of BN50739. We conclude that PAF may play a role in allergic reaction.

Topics: Alveolitis, Extrinsic Allergic; Animals; Azepines; Female; Guinea Pigs; Histamine; Lung; Male; Ovalbumin; Platelet Activating Factor; Prostaglandins F; SRS-A; Thromboxane B2; Triazoles

Methods for the profiling of prostaglandin D2 (PGD2), prostaglandin E2 (PGE2), prostaglandin F2 alpha (PGF2 alpha), 15(S),9 alpha,11 beta-trihydroxyprosta-5Z,13E-dien-1-oic acid (9 alpha,11 beta-PGF2), 6-keto-prostaglandin F1 alpha (6kPGF1 alpha), and thromboxane B2 (TxB2) in bronchoalveolar lavage (BAL) fluids from human subjects by combined capillary gas chromatography-mass spectrometry are described. Aliquots (5 ml) of BAL fluid obtained using a standardized lavage protocol were extracted on octadecylsilyl silica cartridges after addition of 0.8 to 2.0 nanograms of tetradeuterated analogs of PGE2, PGF2 alpha, and 6kPGF1 alpha as internal standards. Eluted analytes and internal standards were prepared for vapor phase analysis by sequential reactions resulting in the formation of methyloxime-pentafluorobenzyl ester-trimethylsilyl ether derivatives. The derivatized analytes were detected by simultaneous monitoring of ions at six different masses characteristic for each of the derivatized prostanoids. The samples were of adequate purity for identification and quantitation of each of the prostanoids with detection limits of 0.1 to 0.2 picograms of each analyte per milliliter of BAL fluid. The time required for analysis of each sample was approximately 30 minutes. Standard curves of unlabeled species of the six prostanoids extracted after addition to BAL fluid were linear over a range from subpicogram to nanogram quantities. The differences between the amounts of prostanoid added and the amounts of prostanoid measured were typically less than 19%, and the intra-assay coefficients of variation for repeated measurements of a single sample were less than 20%. PGE2, PGD2, PGF2 alpha, and TxB2 were detectable in BAL fluids from normal subjects with levels of each of these compounds being less than 2.6 picograms/ml. BAL fluids from patients with lung disease presented qualitative and quantitative profiles of prostanoids markedly different than those from normal subjects. These analytical methods provide a basis for in vivo comparisons of prostanoid profiles in the lower respiratory tract of man and should be readily adaptable for use in a variety of clinical studies.

Topics: Alveolitis, Extrinsic Allergic; Asthma; Body Fluids; Gas Chromatography-Mass Spectrometry; Humans; Prostaglandins; Pulmonary Alveoli; Reference Values; Thromboxane B2