Digestion and mucosal absorption of fat in normal and bile-deficient dogs

¹ Department of Physiology, Indiana University School of Medicine, Indianapolis, Indiana

The role of bile in fat digestion and absorption was investigated by studying the intestinal intraluminar and mucosal cell changes which occur after feeding either cottonseed oil triglycerides or oleic acid to normal dogs and to dogs deprived of bile by cholecystonephrostomy. Although the intraluminar lipids of the bile-deficient dogs contained a higher than normal concentration of monoglycerides, lipolysis, as based on the high concentration of intraluminar free fatty acids, was quite extensive in the absence of bile and comparable to that obtained in normal dogs. The conclusion is that bile does not play an important intraluminar role in fat absorption associated with lipolysis. Mucosal lipid of dietary origin recovered after feeding either triglycerides or free fatty acids to normal dogs was primarily in the form of higher glycerides, whereas that recovered from the mucosa of bile-deficient dogs contained a larger than normal proportion of free fatty acids. This result suggests that the intracellular esterification of the absorbed products of fat digestion is retarded in the absence of bile.