Effect of Beta-Sitosterol on Regression of Hypercholesterosis and Atherosclerosis in Chickens.∗

1. A previously elevated cholesterol concentration in the liver, serum, and aorta of the chicken was reduced by administration of beta-sitosterol in presence or absence of dietary cholesterol, or by withdrawal of dietary cholesterol. 2. Tissue cholesterol concentrations observed as a result of these treatments always approached the normal values. 3. When 4% beta-sitosterol was fed in the diet, total sterol content of liver was slightly lower than in birds fed the basal diet only. Further, total sterol content of the serum and aorta tended to be lower than that of birds fed basal diet only. 4. Atheroma regression in the chicken was accomplished by administration of beta-sitosterol in presence of dietary cholesterol. 5. Atheroma regression in the chicken was paralleled by a drop in cholesterol concentration of the blood and liver.