Comparison of experimental hypercholesterolemia and atherosclerosis in male and female mini-pigs of the Göttingen strain.

The susceptibilities of male and female mini-pigs of the Göttingen strain to experimental hyperlipoproteinemia and atherosclerosis were studied and compared. Hyperlipoproteinemia was induced in groups of pigs of each sex by adding 11.2% egg yolk and 0.5% cholesterol to the diet. The initial increase in the plasma cholesterol concentration was significantly greater in the female animals than in the male ones. In both sexes most of the increase in plasma cholesterol was referable to the low-density lipoprotein fraction. As the experiment proceeded, the difference in the plasma cholesterol level between the sexes became less pronounced. After 18 months on the lipid-rich diet the animals were slaughtered and examined for atherosclerotic lesions. Specimens from the coronary arteries and the thoracic and abdominal aorta were taken for lipid analyses. From colour photographs of the intimal surface of the aorta, the percentage area of visible atherosclerosis in the abdominal part was calculated. Atherosclerotic lesions were present in the coronary arteries and in the abdominal aorta in both sexes. In the abdominal aorta, the results of the lipid analyses, and the calculated percentage area of atherosclerosis, indicated that the degree of atherosclerosis was similar in male and female pigs. In the coronary arteries, the atherosclerosis was more pronounced in the female pigs, as judged from the accumulation of cholesterol.