770 VII. LIPID DISTRIBUTION IN SPECIFIC TISSUES 



(2) Phospholipids and Plasmalogens in the Adrenal Glands 



Brown and collaborators 336 reported that the phospholipids comprise 

 the chief lipid in both the cortex and the medulla of beef adrenal tissue, 

 where they are present to the extent of 3.09 and 2.66%, respectively, of the 

 moist weight. The total lipid content of the beef suprarenal cortex is 

 given as 5.36%, while that of the medullary tissue was found to be 4.83%. 

 No neutral fat was present in this tissue. Although Bloor reports a compar- 

 able level of phospholipids for whole adrenal glands of the guinea pig 

 (4.03%), the total lipid in this organ was 15.84%. Klenk and Friedrichs 40 

 reported that the plasmalogens accounted for 5.5% of the total phosphatide 

 in beef adrenal tissue; the latter amounted to 1.13% of the moist organ. 



(3) Arachidonic Acid in the Adrenal Glands 



Brown, after demonstrating that arachidonic acid is the only highly 

 unsaturated acid in liver lipids, 30 reported the presence of this tetraenoic 

 acid in thyroid, spleen, and suprarenal lipids to the extent of 0.4, 4.0, and 

 5.5%, respectively, of the total fatty acids. 364 In a later communication, 

 the figure for the arachidonic acid concentration of the fatty acids of the 

 whole suprarenal glands was revised upward to 11.2%. 365 The fatty acids 

 in suprarenal lipids other than arachidonic acid were principally palmitic, 

 stearic, and oleic. In a later study, Ault and Brown 366 noted that arachi- 

 donic acid made up 22% of the suprarenal phosphatides, which is the rich- 

 est source of this acid thus far reported. The saturated acids were iso- 

 lated in the following amounts : palmitic, 23.8%; stearic, 11.1%; arachidic 

 2.0%; and myristic, 1.2%. Oleic acid made up about 40% of the total. 



7. Lipids Present in the Spleen 



Under normal conditions, the spleen presents no unusual features is 

 lipid composition. Pfeiffer 367 reported a cholesterol content of 95 milligram 

 per cent based upon moist weight ; of this, about two-thirds was present as 

 the free alcohol. Fresh spleen was found to contain only 2.9% of the total 

 lipids, and most of this belonged to the ether-soluble fraction. 368 No 

 cerebroside is present in normal spleen, although Tropp and Wiedersheim 369 



364 J. B. Brown, J. Biol. Chem., 83, 777-782 (1929). 



366 J. B. Brown, unpublished data; cited by W. C. Ault and J. B. Brown. J. Biol. 

 Chem., 107, 607-614 (1934), p. 607. 



366 W. C. Ault and J. B. Brown, J. Biol. Chem., 107, 607-614 (1934). 



367 G. Pfeiffer, Biochem. Z., 281, 239-243 (1931). 



368 L. Bouisset and C. Soula, Compt. rend. soc. biol, 110, 673-674 (1932). 



369 C. Tropp and V. Wiedersheim, Z. physiol. Chem., 222, 39-43 (1933). 



