Studies in the absorption of fats

Abstract

The general impression of workers in the field of fat metabolism, with regard to the path of absorption, seems to be that while most of the fat enters the circulation by way of the thoracic duct, a smaller portion can be absorbed directly into the blood stream. The most recent discussion of the subject is by Bloor. 1 The results of previous workers are, briefly, as follows: Walther 2 recovered in anesthetized animals only a small fraction of the absorbed fat from the lymph of the thoracic duct. Munk and Rosenstein 3 recovered from the discharged lymph 60 per cent. of the fat fed to a patient with lymph fistula. Frank 4 tied off the thoracic duct after feeding fat and still found the fat of the blood to increase during absorption. Hamburger 5 tied off three equal-sized loops of intestine and in the central loop ligated all lymph vessels. Then after injecting an oil and soap emulsion, he noted that this was absorbed from the central loop despite the tying off of the lymph vessels, although it was distinctly less in amount than in the control loops. Munk and Friedenthal, 6 in a preliminary communication, describe experiments similar to those of Frank, but use more precautions, such as tying off the ductus lymphaticus communis dexter, besides the thoracic duct, to avoid possible anastomoses. In general, their findings are the same as those of Frank and they also conclude that the blood can absorb products of fat digestion directly from the intestine.

d'Errico 1 approached the subject from a different angle. He determined the amount of ether extract in simultaneous samples of portal and jugular blood of an animal near the height of fat absorption after a meal.