CARDIOVASCULAR LESIONS AND CHANGES IN BLOOD COAGULATION AND FIBRINOLYSIS ASSOCIATED WITH DIET-INDUCED LIPEMIA IN THE RAT*

Abstract

Among the animals in which atherosclerosis has been experimentally induced, the rat has been the object of particular interest because of its omnivorous dietary habits (1). In 1956, Fillios, Andrus, Mann and Stare (2) reported induction of atherosclerosis in this animal, using a diet that included cholesterol, sodium cholate, and thioura- cil. Yet in these and subsequent experiments by other investigators, vascular thrombosis, generally considered a secondary complication of athero- sclerosis, was noticeably rare (3). In 1959, Hartroft, O'Neal and Thomas (4, 5) added large amounts of butter to the basic diet used by Fillios and co-workers and reported a high percentage of thrombosis and myocardial infarction. They especially noted that thrombotic lesions may de- velop without accompanying vascular changes, and they reported that a number of these thrombi were found in cardiac chambers. Many have questioned the significance of such lesions devel- oped under severe experimental conditions. More recently, Gresham and Howard (6) re- ported confirmation of the experiments of Hart- roft and associates. It appeared that these ex- periments might provide a suitable model to appraise the still controversial connection between lipemia and clotting changes in vitro as well as the relevance of all this to the mechanism of thrombosis in vivo.