444 ELIOT R. CLARK AND ELEANOR LINTON CLARK 



DISCUSSION OF THE RESULTS IN CONNECTION WITH THE QUES- 

 TION OF FAT ABSORPTION 



In the present investigation we were concerned chiefly with 

 the question of the reaction of the growing lymphatic toward an 

 external stimulus, which in this case was represented by the in- 

 jected fat. Therefore, the scope of these experiments did not 

 enable us to deal with the problem of fat absorption except in an 

 incidental manner. 



According to a recent summary by Bloor (2), most investiga- 

 tors now agree with the findings of Pfliiger (22, 23) that fat in the 

 small intestine is saponified through the action of the pancreatic 

 ipase and the bile salts and is absorbed by the intestinal mucosa 

 in the form of water-soluble soap and glycerol. However, 

 Rossi (25) and Levites (18) claim that part at least of the fat 

 is absorbed in the form of fatty acids. The work of Kastle and 

 Loevenhart (15) on the reversible action of lipase on ethyl buty- 

 rate, which has been confirmed by Pottevin (24) with regard to 

 the higher fats, and the discovery of Loevenhart (19) that lipase 

 is a normal constituent of the epithelial cells of the intestinal 

 mucosa, make it clear that the products of the lipolysis are 

 resynthesized within the intestinal cells. Sixty per cent of the 

 absorbed fat is known to be taken up by the lymphatic system 

 and reaches the thoracic duct in the form of neutral fat. The 

 rest has been shown by Hamburger (12), by D'Errico (7) and 

 by Mendel and Daniels (20) to be conveyed to the liver by 

 means of the portal circulation. The fat remains within the 

 blood, suspended in a finely divided state, for about two hours 

 after intestinal absorption and then disappears. Bloor (1, 2) 

 has shown that the fat in the blood is taken up, to a large extent, 

 by the blood corpuscles, both red and white, and there trans- 

 formed into lecithin. Leathes (17) investigated the later stages 

 of fat absorption and has shown that the fatty acids are de- 

 saturated in the liver in prepartion for the process of oxidation. 



The mechanism by which the fat which is resynthesized in 

 the intestinal mucosa, reaches the central lacteals of the villi, 

 has not been clearly demonstrated. Loevenhart (19) advanced 



