Circulation of Labeled Albumin Through the Aortic Wall of the Dog

Abstract

Data are presented which support the concept that albumin enters the inner layer of the aortic wall by passage from the lumen of the aorta across the intimal endothelium. The rate of movement of albumin from serum into the aortic wall is much greater proximally where the aorta is wide than distally where it is narrow. Thus the rate correlates with the circumferential tension to which the aortic wall is subjected. The hypothesis is advanced that circumferential tension acts as a major determinant of transendothelial transfer of proteins into the aorta by widening the endothelial intercellular spaces through which the transfer occurs.