Thromboxne A 2 (TXA 2) and prostacyclin (PGI 2) play an important role in the development of thrombosis.
In this study, plasma TXB 2 (stable metabolite of TXA 2) and 6-keto-PGF1a (stable metabolite of PGI 2) concentration in several diseases were measured by RIA.
Results were as follows.
1) Plasma TXB 2 concentration was 223.4±47.9pg/ml (Mean±SD) in normal controls and significantly increased in patients with DM (328.4±45.3), IHD (320.3±99.1), liver cirrhosis (321.2±112.5), pancreatitis (342.2±189.9) and DIC (557.0±207.5).
2) Plasma 6-keto-PGF1a concentrtion was 9.1±6.9pg/ml in normal controls. There was no significant difference in 6-keto-PGF1a concentration in several diseases.
3) There was a positive correlation between plasma TXB 2 and 6-keto-PGF1a concentration. (r=0.22)
4) TXB 2, generated by exogenous thrombin, showed significant increase in platelets of diabetics with microangiopathy, compared with normal controls.
5) TXB 2 generation by exogenous arachidonic acid also showed significant increase in platelets of diabetics.
6) There was an negative correlation between plasma TXB 2 concentration and serum HDL-cholesterol. (r=-0.31)
From these findings, plasma TXB 2 concentration seemed to be increasing in diseases with thrombotic tendency. Moreover, it was suggested that in diabetics with microangiopathy, not only cyclooxygenase but also phospholipase activity in platelets are significantly accelerated.