Butter, corn oil and fibrinolysis in rats.

CONSIDERABLE evidence has accumulated suggesting that 2 factors are involved in coronary thrombosis in man: (1) a local factor (usually atherosclerosis) ; and (2) a hematologic factor (procoagulative, antifibrinolytic, or both)." Data obtained from this and other laboratories during the past several years indicate that the ingestion of certain fatty substances might be involved in both the local and hematologic factors. We have recently reported a dietary method for the production of coronary thrombosis and myocardial infarction in rats. ' 5 In those experimental animals, the degree of arteriosclerosis (local factor) has been surprisingly minimal at even the sites of thrombosis and has led us to believe that the diet was affecting principally the hematologic factor. Our attention has been directed toward the development of methods for the study of fibrinolysis. A method was needed that was as nearly objective as possible, reproducible, and capable of comparisons of rats on thrombogenic diets with those on nonthrombogenic diets. For objectivity we chose to use an electronic device called a Thrombelastograph,* which provides a permanent, measurable record of at least certain aspects of blood clotting and clotlysis.' 8 For reprodueibility and comparability, we have utilized several purified or semipurified additives that permit clotting and lysis of plasma from rats at will. Thus standard conditions can be created under which clotting and lysis times and clot-firmness of normal plasma can be measured with