242 III. DIGESTIBILITY OF FATS 



saturated acids, any method in which the label is not uniformly distributed 

 will give erroneous results. Weijers and van de Kamer 129 have shown that 

 unsaturated acids may be almost completely absorbed (90%) when the 

 overall absorption of dietary fat is only 70%. Since there may not be 

 any diminution of the hydrolytic activity of pancreatic lipase, and a delay 

 in absorption of particulate fat occurs in celiac disease, the excessive 

 lipolysis may result in the separation of saturated fatty acids which can- 

 not be absorbed. These factors render the use of absorption studies on 

 labeled fats of limited value in assessing abnormal fat absorption. 



{2) General Changes Occurring in Defective Fat Absorption 



The abnormalities in fat absorption can be determined both from the 

 intraluminar phase and from tests of the absorptive capacity of the upper 

 intestine. To ascertain the condition of the fat in the intestine, samples 

 of intestinal contents obtained by the aid of a Miller-Abbott tube are 

 examined microscopically to determine the state of emulsification after 

 the administration of olive oil. 128 The absorptive capacity of the upper 

 intestine may be assessed by intraduodenal administration of glucose and 

 urea, and subsequent determination of the rise in concentration of these 

 substances in the systemic blood. 



Another factor of importance in sprue is the presence of excessive mucus 

 in the small intestine, which interferes with absorption by mechanical 

 action. Although the amount of mucus cannot be determined directly, 

 it can be estimated radiographically by following the extent of flocculation 

 which occurs after the administration of a simple suspension of barium 

 sulfate. 128 



According to Frazer, French, and Thompson, 130 there is a rough quanti- 

 tative relationship between the amount of mucus and the size of the 

 floccule formed. 



Another index for assessing whether or not abnormal fat absorption ob- 

 tains is defined as the distributive phase. To determine this response, 

 serial counts of chylomicrons of the blood are made by a standardized 

 technic, 131 after a test dose of 24 g. of butterfat. 



129 H. A. Weijers and J. H. van de Kamer, Fat Absorption in Normal and Abnormal 

 Infants and Children, with Special Reference to Coeliac Disease, Public. 113, Centraal 

 Inst, voor Voedingsonderzoek, T. N. O., Dekker <fe Van de Vegt, Utrecht, 1950, pp. 

 9-82. 



150 A. C. Frazer, J. M. French, and M. D. Thompson, Brit. J. Radiol, 22, 123-136 

 (1949). 



131 A. C. Frazer and H. C. Stewart, J. Physiol., 95, 21P-23P, 23P-24P (1939). 



