METHODS FOR STUDY OF FAT ABSORPTION 123 



tion. In the so-called Lieberkiihn crypts, which are not concerned with 

 absorption, erepsin, enterokinase, lipase, and sodium carbonate are pro- 

 duced. Mucus-forming cells are scattered throughout the intestinal epithe- 

 lium. 



5. Methods for the Study of Fat Absorption 

 and Lipid Absorption in General 



The most satisfactory procedures for the investigation of lipid absorption 

 from a quantitative standpoint are those which involve a determination of 

 the rate of disappearance of the substance under consideration from the 

 gastrointestinal tract. Such procedures do not afford any information as 

 to the form in which the component is absorbed or as to the pathways in- 

 volved in the transport of the material from the intestine. On the other 

 hand, methods of study of fat absorption which will reveal the latter data, 

 such as thoracic cannulation, are less adapted to reveal quantitative rela- 

 tionships. One would expect the best results from those procedures which 

 involve the use of unanesthetized animals. 



(1) Thiry-Vella Fistulas 



The intestinal loop devised almost a hundred years ago by Thiry (also 

 spelled "Thiery"), 699 and modified by Vella, 600 has been the classical method 

 for the study of absorption of foodstuffs since it was originally described. 

 The simple Thiry fistula involves the excision of a section of the intestine. 

 The exposed ends remaining after the removal of the section are connected 

 to form an anastomosis. One end of the excised section is fastened to the 

 abdominal wall. The rest of the separated portion of gut is allowed to 

 remain in the peritoneal cavity after the open end is tied off with a suitable 

 ligature, to prevent drainage of the intestinal juice into the peritoneal cav- 

 ity. During all operative procedures, the blood and nerve supply to the 

 loop are kept intact, so that they will continue to function normally after 

 the operation is completed and the wound has healed. In the Vella modi- 

 fication of the operation, both ends of the excised loop are brought to the 

 abdominal surface. About 3 to 4 cm. of the gut are allowed to project 

 above the surface to take care of the sloughing off of the injured portion 

 of the intestinal section adjacent to the area where it has been cut. 



The double fistula appears to be more satisfactory than the single one, 



599 L. Thiry, Sitz.-Ber. Akad. Wiss., Wien, Math.-naktrw. Klasse, 50, Abt. I, 77-96 

 (1865). 



B00 S. Vella, Untersuch,, Naturlehre (J. Moleschott), IS, 40-74 (1883). 



