Spontaneous Arteriosclerosis of the IVIesenteric, Renal, and Peripheral Arteries of Repeatedly Bred Rats

• Considerable emphasis is given to the investigation of the coronary and cerebral arteries because of the dramatic consequences of arteriosclerosis in these vessels. It is well known that the severity of arterial disease differs from one anatomical site to another. Hence greater emphasis should be placed on understanding the anatomical distribution of arteriosclerosis, particularly since recovery from the acute clinical complications of coronary and cerebral arteriosclerosis may depend largely upon the physiological and anatomical integrity of more peripheral arteries, such as those of the mesentery, kidney, and extremities. In this laboratory, we have found that male and female rats, bred repeatedly, will develop arteriosclerosis spontaneously. The arterial lesions begin in the abdominal aorta, and, as the disease progresses, arterial degeneration appears in the arch and thoracic segments of the aorta as well. As a later development, the coronary arteries also show evidence of arterioslcerosis. In addition, arteriosclerosis tends to appear earlier in the endocardial than in the epicardial branches of the coronary arteries. The cerebral arteries appear to be the most resistant, or the