ABSORPTION 



281 



The dry residue was weighed and the fatty acid and fat estimated 

 in it. The results were : 



(1) 84-3 neutral fat 



(2) 64-6 



15-7 fatty acid. 

 35-4 



They showed that the synthesis is taking place in the mucosa, 

 and that this is at any moment incomplete. 



Moore's conclusion is that the synthesis of neutral fat takes 

 place in the living cells of the mucosa, and is not brought about 

 by enzymic action. It is, he says, theoretically highly improbable 

 that the lipase should in the intestine cause almost complete 

 conversion into fatty acid and glycerine, and within the columnar 

 cells cause a complete reversal into neutral fat. Such a reversal is 

 the function not of an enzyme but of the living cell wherein there is 

 a supply of external energy and means for its transformation. 



The absorption of fat is most complete when a fat-rich diet 

 is given. The taking of carbohydrate does not interfere with the 

 absorption of fat ; but less proteid is absorbed when the other two 

 food- stuffs are given than when proteid is fed alone. Muscular 

 work does not influence the assimilation of fat (Atwater). 



No fat-splitting ferment exists in chyle. In the blood, on the 

 other hand, Connstein and Michaelis have discovered that fat is 

 changed into an easily reversible, soluble, filtrable, and dialysable 

 form, by means of which change it is transported into the tissues, 

 for the fat droplets which enter the blood from the thoracic duct 

 cannot wander out of the intact capillaries. Connstein and 

 Michaelis collected the chyle of a fat- fed dog and injected it into 

 the vein of another, thereby raising the fat content of the blood 

 five-fold. They found no trace of fat in the tissue lymph flowing 

 from the thoracic duct of this animal, but the amount of dialys- 

 able material in the lymph increased, at the same time the fat in- 

 troduced into the blood steadily diminished in amount. Thus, at 

 3.10 P.M. 85 c.c. of chyle were injected containing 6-145 grm. fat. 



