ABSORPTION AND TRANSPORT OF FATS 143 



or in rats having an exogenous ketonuria.669a Voegtlin, Dunn, and Thomp- 

 son 670 showed that glycerol can replace glucose in counteracting the hypo- 

 glycemic and toxic effects resulting from insulin injection. One must predi- 

 cate that glycerol is absorbed from the intestine and is converted to glucose 

 before it is able to produce either of the above effects. 



Cremer 671 has carried the proof of absorption one step further by account- 

 ing for 40% of the glycerol given to phlorhizinized dogs as "extra-glucose" 

 in the urine, while Liithje 672 reported essentially similar results for depan- 

 creatized animals. Chambers and Deuel 673 were able to demonstrate a 

 practically quantitative conversion of glycerol to glucose in phlorhizinized 

 dogs when the polyhydric alcohol was given orally, and a 70% transforma- 

 tion after subcutaneous administration. Glycerol also yields glycogen. 669a 



The absorption of the fatty acid moiety from the intestine was demon- 

 strated as early as 1868 by Radziejewski, 674 who fed the acids in the form 

 of soaps. Perewoznikoff 675 reported that a mixture of soap and glycerol 

 was absorbed and synthesized into fat ; he showed that, after this mixture 

 was fed, the lacteals had the same milky appearance as after a fat meal, 

 and also that the epithelial cells contained fat globules. Many other 

 workers have confirmed the early results with fatty acids and soaps. 620 » 676,677 

 Jeker 677 reported the presence of free fatty acid in the mucosa within ten to 

 twenty minutes after fat feeding, as determined histologically; by the sixth 

 hour the free fatty acid had disappeared and had been replaced by neutral 

 fat. Terroine 678 also reported that the rate of hydrolysis of fats by pan- 

 creatic juice in vitro has a direct relationship with the speed of absorption 

 of fat. 



Another indication of the absorption of the free fatty acids is obtained 

 from the studies with simple esters of fatty acids. Thus, it was demon- 

 strated that fatty acids were absorbed when given as ethyl esters, 679 as 

 amyl esters, 620 or as the optically-active mannite esters. 680 Frank 679 found 



669a I. Shapiro, J. Biol Chem., 108, 373-387 (1935). 



670 C. Voegtlin, E. R. Dunn, and J. W. Thompson, Am. J. Physiol, 71, 574-582 (1924- 

 1925). 

 871 M. Cremer, Munch, med. Wochschr., 49, 944 (1902). 



672 H. Liithje, Dent. Arch. klin. Med., 80, 98-104 (1904). 



673 W. H. Chambers and H. J. Deuel, Jr., J. Biol Chem., 65, 21-29 (1925). 



674 S. Radziejewski, Arch. path. Anat. Physiol. (Virchow's), 48, 268-286 (1868); 56, 

 211-219 (1872). 



676 A. Perewoznikoff, Zentr. med. Wiss., 14, 851-852 (1876). 



678 1. Bang, Biochem. Z., 91, 111-121 (1918). 



977 L. Jeker, Arch. ges. Physiol. (PflUger's), 237, 1-13 (1936). 



878 E. F. Terroine, Ann. set. nat., Zool, [10], 4, 1-397 (1920). 



879 O. Frank, Z. Biol, [2], 18 (86), 568-593 (1898). 



880 W. R. Bloor, /. Biol. Chem., 11, 141-159, 429-434 (1912). 



