The role of human coagulation factors in serum-induced thrombosis

Effects of plasma and serum on arterial endothelium

Electron microscopic study of the femoral artery of rats following a single brief intra-arterial infusion of two different types of rat plasma and of rat serum led to the following findings and conclusions: 1. Plasma from heparinised blood caused no endothelial injury whatsoever whereas plasma from citrated blood damaged the arterial endothelium. Since the intra-arterial infusion of citrate alone produced an endothelial injury that was similar to that induced by plasma from citrated blood, it is very likely that the endothelium-injuring effect of the latter was due to its citrate content. 2. Serum obtained from clotted blood injured both the endothelium and some myocytes of the arteries into which it was infused. This injury was possibly due to the proteolytic or other actions of activated clotting factors, which are known to be present in serum but absent from plasma. The implications of these findings for certain areas of experimental and human pathology are discussed.

Effect of lactation suppressants on the coagulation mechanism

The effect on the coagulation mechanism of lactation suppressants was determined by comparing observations on a group of untreated women and two other groups, one receiving Vallestril (methallenestrill 20 mg) and the other Ortho-Novum 5 (5 mg norethindrone and 0.075 mg mestranol). Blood was drawn on the first, fourth and tenth days post partum. Patients given Ortho-Novum 5 showed a continued significant elevation of levels of factors VIII and IX for the duration of the study, and the partial thromboplastin time reflected this increase on days 4 and 10. Vallestril appeared to have the same effect on factors VIII and IX, although to a lesser, nonsignificant degree. In addition, the day 10 levels of fibrinogen and factors VII and X, as well as platelet adhesiveness, of the untreated group were lower than those of the groups undergoing treatment, although the medication had been discontinued five days previously. However, this difference was not statistically significant.In view of the growing evidence of the increased incidence of thromboembolic disease during the puerperium, it is perhaps unwise to give drugs that cause changes in the plasma coagulation system, such as those we have described, to patients who are already in a hypercoagulable state.

Plasma factor IX levels in patients given hexoestrol or stilboestrol to suppress lactation

A single injection of hexoestrol, 45 mg., is effective in suppressing lactation. Given in this way hexoestrol causes a small rise in plasma factor IX levels, of shorter duration than that produced by a customary and equally effective oral course of stilboestrol. With hexoestrol the plasma factor IX levels reverted to normal by the sixth day of the puerperium.

Blood Coagulation and Thrombotic Disease

The role of blood coagulation in the pathogenesis of thrombotic disease as well as atherosclerosis is receiving renewed attention, and has been greatly extended into the area of therapy. The clotting mechanism has been delineated in accordance with most recent information, with particular reference to the early phases and the coagulation balance. The close relationship between clotting and proteolytic phenomena is considered, and the concept of hypercoagulability is critically scrutinized. Experimentally induced thrombosis by means of serum factors is reviewed in support of this concept. Also discussed is the place of lipids in coagulation and atherosclerosis in an attempt to embrace the lipid theory of the pathogenesis of atherosclerosis with current concepts of clotting. Finally, certain aspects of anticoagulant action are covered.