The mechanisms provided for the transport of various food materials in the blood and across cellular barriers depend on the nature of the foodstuff. While amino acids and the simpler carbohydrates are generally soluble in water, fatty acids and most of their compounds are insoluble in an aqueous medium. For this reason the transportation of fat in the body presents a unique problem. In recent years research workers have resorted to novel methods, involving the use of fatty acids containing isotopes or radioactive elements in studies bearing on this problem; such methods have served to add considerably to our knowledge of the carriage of fat.
In a timely review Bloor1 has summarized some of the more recent facts and ideas bearing on the problem of the transport of fat in the body. With regard to the transfer of fat across the intestinal mucous membrane, it may be recalled that