Recent studies have clarified some aspects of fatty acid transport. The results promise to be of clinical importance, since fat, as a major energy source and as a component of body structure, plays a central role in chronic diseases of metabolism. For example, obesity can be conceived as an abnormal balance between the total amount of fatty acid stored in adipose tissue and its availability as substrate for working cells. Arteriosclerosis is characterized by abnormal deposits of fatty acid esters. Diabetes, although usually defined by high blood sugar, is in fact a general disturbance of metabolism, and its most dangerous complications can be traced to faulty handling of fatty acids.
During the past few years a number of laboratories, including ours, have been studying a fatty acid fraction which is remarkable for both its speed of turnover and its close relation to the state of carbohydrate metabolism. This fraction, the