Passage of labeled cholesterol into the aortic wall of the normal dog.

In the normal dog the rate of movement of cholesterol from the serum into the inner layer of the aortic wall is greatest at the proximal end of the aorta and decreases progressively along the length of the aorta until in the terminal aorta the rate is only about one sixth that in the proximal aorta. A similar gradient of rates was previously demonstrated for albumin which enters the aortic wall about three times as fast as cholesterol. The similarity of the gradients and the relative magnitude of the rates for cholesterol and albumin support the concept that cholesterol is carried into the aortic wall of the normal dog by the passage of the lipoproteins of which it is a part.