Effect of Estrogens on Blood Clotting and Plasmin Systems

In order to clarify the controversial findings concerned with the effect of estrogens on coagulation and plasmin systems, various preparations of estrogen having different chemical structures, i.e., desoxyestrone, estradiol and Premarin R, were administered to human subjects and the factors of blood coagulation and the plasmin systems were determined. There was no significant change in the factors of the coagulation system excepting a slight decrease in the recalcification time with the administration of estriol or Premarin R, slight elevation of Factor VII with Premarin R, and a slight prolongation of the thrombin time with estradiol, estriol and Premarin R. On the other hand, a marked change was noted in the plasmin system, namely, a decreases in the total plasmin and antiplasmin, and a marked elevation of the spontaneous caseinolytic activity of the euglobulin fraction.