CHOLESTEROL-ESTER STEATOSIS 421 



Cholesterol-ester Steatosis. The problem of the process 

 of fatty change would be incompletely dealt with were the 

 author not to mention an entirely new phase, that of choles- 

 terol-ester steatosis. 



As previously stated (v. Vol. I of this series, p. 324, Chem- 

 istry of the Tissues) the esters of cholesterol with the higher 

 fatty acids are of interest both from a physiological and a 

 pathological point of view. These esters have been demon- 

 strated in wool fat, in epidermal scales by Salkowski, 64 in the 

 cutaneous fat by Unna, 65 and in the blood serum by 

 Hiirthle. 66 It has been shown in Bb'hmann's laboratory 67 

 that in the acetic-ether extract of the liver, along with free 

 cholesterol, a certain amount of cholesterol esters is present, 

 and that the liver also contains an enzyme capable of split- 

 ting these esters. What is of especial interest to us, how- 

 ever, is the fact that a crystalline, doubly refractive sub- 

 stance found in fatty kidneys has been determined by Pan- 

 zer, 68 in Ernst Ludwig's laboratory, as an ester of cholesterol 

 with an unsaturated higher fatty acid. This discovery has 

 been fully confirmed by Windaus 69 by his digitonin method 

 of determining cholesterol ; and we are justified in assuming 

 that the cholesterol esters actually take an important part in 

 the formation of doubly refractive substances in fatty tis- 

 sues. The pathologist Aschoff has in fact seen fit to regard 

 cholesterol-ester fatty change as being a form of fat metab- 

 olism of at least equal importance and of equivalent origin 

 to glycerol-ester fatty change; and he intrusted his pupil, 



M E. Salkowski, Arb. a. d. Pathol. Instit., Berlin, A. Hirschwald, 1906; 

 Biochem. Zeitschr., 23, 362, 1910. 



65 Unna and Golodetz, Biochem. Zeitschr., 20, 469, 1909. 



60 Hiirthle, Zeitschr. f. physiol. Chem., 21, 331, 1895. 



87 K. Kondo (Rohmann's Lab., Breslau), Biochem. Zeitschr., 26, 238, 243, 

 252, 427, 437, 1910. 



68 T. Panzer (E. Ludwig's Lab., Vienna), Zeitschr. f. physiol. Chem., 48, 

 519, 1906; 54,239, 1907. 



69 A. Windaus (Freiburg), Zeitschr. f. physiol. Chem., 65, 110, 1910; cf. 

 also J. Pringsheim, Biochem. Zeitschr., 15, 52, 1907. 



