Effect of Estrogens on Blood Clotting and Plasmin Systems

Abstract

In ordor 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.A hypercoagulemic state is observed during pregnancy characterized by a decrease in the clotting time of whole blood, a decrease in r (reaction time) and K (coagulation time) and an increase of ma (maximal amplitude) in the thrombel astogram as well as increases in fibrinogen, prothrombin, Factor V and Factor VII.1-5 At the same time, increases in the plasmin system including increases in the total plasmin (caseinolytic activity of the SK-euglobulin), and spontaneous proteolytic activities of the euglobulin fraction are also found in pregnant women, 6-8 as if they play a role in buffering the hypercoagulemic state . These changes seem to be under neurohormonal control especially by the sex hormones. It was reported that Premarin R, a mixture of sodium salts of estrone sulfate and equilin sulfate from the urine of pregnant mares, can produce increases of fibrino gen, Factor V and Factor VII.9 It was also noted that estrogens have a depress ing effect on the blood cholesterol level."," If it is true, as is generally accepted, that hyperlipemia can produce a hypercoagulemic state, the above actions of * The 16th report on Pathophysiology of Plasmin System 219

Inhibiting Activity of Estrogens on Capillary Permeability

“…However, we observed that various estrogen prepara tions did not seem to cause significant changes in the coagulation and fibrinolysis systems. 4 On the other hand, since the report of Schiff and Burn,5 it has been generally accepted that intravenous administration of certain estrogens has a definite effect on the ground substance rather than on the intravascular factors, of which importance was stressed in the past. This has been supported by a number of authors.…”