Toshio Asada

Analysis of thromboxane B3 converted from eicosapentaenoic acid in human platelet rich plasma by gas chromatography/mass spectrometry

Gas chromatographic mass spectrometric determination of thromboxane B3 (TXB3) synthesized from platelet is described. Eicosapentaenoic acid (EPA) was added to human platelet rich plasma and after the reaction the exstraction was carried out. Plasma thromboxanes were run through an Amberlite XAD-2 and SEP-PAK silica cartridge, and then chromatographed using silicagel thin layer plate to remove interfering materials, such as 6-keto-prostaglandin F1 alpha. Extracted thromboxanes were converted into the methoxime-dimethylisopropylsilylmethyl ester derivatives and they were measured by gas chromatography/ammonia chemical ionization mass spectrometry. Three peaks were obtained on the gas chromatogram which were presumed to be 3-series metabolite product TXB3 and their related substances. Results indicates the human platelet may easily convert EPA to TXB3 by adding EPA to PRP without adding arachidonic acid.

Dynamics of kallikreinogen under hemodialysis.

There are many complications due to hemodialysis, causes of which seem to lie under disorders of the coagulation system, fibrinolytic system, and kinin system. Therefore, it is important to understand the dynamics of these systems during hemodialysis. Accordingly, kallikreinogen, plasminogen, plasmin inhibitors, contact factor, antithrombin, and prothrombin were assayed during the experimental dialysis, experimental ultrafiltration and clinical hemodialysis. Plasmin inhibitors decreased remarkably by dialysis. They then recovered the pre-dialytic values as time went on. Kallikreinogen did not show any definite tendency immediately after the beginning of dialysis, but two hours later its value rather increased relative to thepre-dialytic value. It was supposed that this increase was caused by reactive hyperproduction due to gradual consumption of kallikreinogen. Contact factor slightly decreased by dialysis, whereas prothrombin and antithrombin decreased apparently. When hemodialysis is practiced, it is necessary to fully realize that the coagulation system, fibrinolytic system, and kinin system might lose their balance.