156 II. DIGESTION AND ABSORPTION OF FATS 



On the other hand, Berry and Ivy 737 were unable to demonstrate the pres- 

 ence of mineral oil in the lymph obtained from the thoracic duct of dogs, 

 when various emulsions of mineral oil ranging in particle size from 200 to 

 0.5 n and less were introduced into the alimentary tract. In spite of this 

 negative result, the positive findings are sufficiently numerous to suggest 

 strongly that a mechanism may exist in the intestinal membrane which 

 will allow the absorption of particulate matter having a diameter of less 

 than 0.5 m- 



According to the Partition Hypothesis, fatty acids pass through the mem- 

 brane, as do other water-soluble compounds or complexes. However, in 

 view of the fact that fats are only partially hydrolyzed and remain largely 

 in the form of glycerides, it is necessary to consider the mechanism for their 

 absorption. One possibility would be that they are dispersed in water in 

 the form of phosphorylated compounds. Under such conditions, an ana- 

 tomical structure for particulate absorption would not be required. How- 

 ever, since the phospholipids appear to be broken down in the intestine and 

 are resynthesized in the intestinal wall, passage through the intestinal 

 membrane in this form would appear to be impossible. Since absorption 

 of triglyceride fat in molecular dispersion is ruled out, Frazer 645 considers 

 that the alternative is passage of the fat through the intestinal membrane 

 in particulate form. 



d\ Adrenalectomy and Fat Absorption: The alterations in fat absorp- 

 tion brought about by adrenalectomy can be readily explained by the Parti- 

 tion Theory. Since the cortical hormones control normal electrolyte bal- 

 ance, they should likewise control the absorption of fat particles which 

 carry a negative charge. 729 Verzar and Laszt, 705,706 Bavetta et al., 709 

 and Frazer 645 agree that fat absorption is depressed following adrenalectomy. 

 According to Verzar and Laszt, 705 - 706 the decreased absorption is to be as- 

 cribed to interference with phosphorylation, which they consider to be an 

 essential process in fat absorption ; this process is controlled by the cortical 

 hormones. However, according to Frazer, 645 other workers failed to con- 

 firm the fact that phosphorylation is a prerequisite for absorption of fat, 738 

 carbohydrate, 739-741 or vitamins. 742 Since the normal fat absorption was 



737 1. M. Berry and A. C. Ivy, Am. J. Physiol, 162, 80-87 (1950). 



738 N. Stillman, C. Entenman, E. Anderson, and I. L. Chaikoff, Endocrinology, 81, 

 481-485 (1942). 



739 H. J. Deuel, Jr., L. F. Hallman, S. Murray, and L. T. Samuels, /. Biol. Chem., 119, 

 607-615 (1937). 



740 W. G. Clark and E. M. MacKay, Am. J. Physiol, 187, 104-108 (1942). 



741 T. L. Althausen, E. M. Anderson, and M. Stockholm, Proc. Soc. Exptl Biol Med., 

 40,342-344(1939). 



742 W. G. Clark, Endocrinology, 28, 545-554 (1941). 



