ヒト胎盤トロンボモジュリンの生化学的性質の検討

抄録

To evaluate the biochemical properties of placental thrombomodulin (TM) in normal pregnancy and toxemia of pregnancy, immunoreactive solubilized TM in 30, 000xg fraction which contained 80% of plasma membrane was measured by ELISA, and the biological activity of TM in 30, 000xg fraction was estimated by protein C activation method.
The levels of TM antigen per mg protein significantly increased during normal pregnancy, and the highest level was detected at 27-31 weeks of gestation. There was no significant difference in the levels of TM antigen between normal pregnancy and toxemia.
The Kd of thrombin for TM was 1.10-2.62nM and showed no significant difference in normal pregnancy and toxemia, and Vmax of thrombin-TM complex for protein C activation also showed no significant difference in normal pregnancy and toxemia.
These data suggest that placental TM has no difference between biochemical properties of normal pregnancy and those of toxemia. Moreover, it is suggested that the increase of TM antigen in normal placenta along with gestational age may be essential to maintain the normal coagulation and fibrinolysis systems in placental circulation in late pregnancy.