Myocardial infarction in rats fed diets containing high fat, cholesterol, thiouracil, and sodium cholate. Circulation

Investigators have produced arteriosclerosis in experimental animals by dietary means for almost half a century. In contrast to the situation in man, however, all previous reports indicate that complicating thrombosis and infarction have been extremely rare in experimental animals. The current report presents dietary regimens by means of which the authors have produced significant numbers of myocardial and renal infarets in rats (6 of 10 in one group and 4 of 10 in each of 2 others). It is notable that thrombo-sis occurred before the appearance of severe structural changes in the arterial walls, although abundant fat could often be demonstrated histochemically. FOR half a century experimental patholo-gists have known that arterial damage fol-lowed the feeding of cholesterol to rabbits. Within the last decade similar lesions have been produced in rats by a variety of methods, all more complex than that which suffices for the rabbit. A few reports1-3 of isolated ex-amples of myocardial infarction developing in animals subjected to these procedures have recently appeared. But we are unaware of any established method for the dietary pro-duction of myocardial infarction in signifi-cant percentages of experimental animals. The foregoing suggests that factors respon-sible for atheromatous changes in both experi-mental animals and man, may not be identi-cal with those responsible for the complica-tions of the disease-coronary arterial throm-bosis and myocardial infarction.4 For several years we have investigated factors influencing the clotting mechanism, particularly those concerned with Clot lysis.5-8 Also, we have emphasized9 the need for an experimental model for studying mechanisms not only for changes in arterial walls but also occlusive thromboses. With this object, an attempt was made to combine a number of conditions which together might produce ar-terial damage and occlusion with infarction