766 • VII. LIPID DISTRIBUTION IN SPECIFIC TISSUES 



cited an even lower figure for the beef cortical tissue (0.255%). On the 

 other hand, Parhon and Cahane 335 reported a value as high as 10.9% for 

 the cholesterol content of the suprarenal cortex of the cat. The cholesterol 

 content of the cortical tissue of guinea pigs is intermediate between these 

 extremes; it is recorded as 3.5 to 6.7% by Parhon and Cahane, 335 and 

 as 3.25% by Whitehead et at. 331 The figure is reported by Oleson and 

 Bloor 338 as 1.84% for the whole gland. Although the ester cholesterol 

 comprises 81% of the total adrenal cholesterol in the guinea pig, 338 it makes 

 up only 10% of the total in the cortex, and 15% in the medullary tissue 

 of cattle. 334 



As early as the first week of life, the cholesterol content of the suprarenals 

 was high in comparison to its level in the spleen, liver, and lungs of the 

 rat; it increased further as the animals became older. Fasting caused 

 some decrease in free cholesterol, but mostly in ester cholesterol, in the 

 cortical tissue. 338 Parhon and co-workers 335,339 found that the cholesterol 

 content of the adrenals varied inversely with the water content, but that 

 thyroidectomy, splenectomy, and thyroxine injections caused only slight 

 changes in this component. 339,340 However, when guinea pigs were an- 

 esthetized with chloroform or nitrous oxide, not only did the cholesterol 

 level of the suprarenal gland fall, but a similar situation obtained with 

 respect to the lecithin content. 341 



Although the cortex of the adrenal gland is of prime importance in the 

 case of cholesterol, actually the differences in lipid composition of the 

 cortex and medulla of cattle are minimal. It is not known whether or not 

 a similar uniformity in composition in the two portions of the gland, re- 

 spectively, obtains in species other than cattle. The data on cattle are 

 summarized in Table 19. 



An increase in the amount of cholesterol in the adrenal gland of rats has 

 been shown to result from the feeding of rapeseed oil. 342 Carroll 343 proved 

 that a similar phenomenon results when erucic acid, which is the chief 

 component of rapeseed oil, is given to rats. Of the other fatty acids tested, 

 only nervonic acid (present in cerebrosides and in sphingomyelin) was 

 shown to elicit a response comparable to that associated with erucic acid. 



337 R. Whitehead, M. C. Oleson, and W. R. Bloor, unpublished observations; cited by 

 W. R. Bloor, Biochemistnj of the Fattij Acids, Reinhold, New York, 1943, p. 221. 



338 M. C. Oleson and W. R. Bloor, /. Biol. Chem., 141, 349-354 (1951). 



339 C. I. Parhon, A. Blinov, and M. Cahane, Compt. rend. soc. biol., 109, 239-240 (1932). 



340 C. I. Parhon, C. Parhon-Stefanescu, and I. Ornstein, Compt. rend. soc. biol., 121, 

 187-189 (1936). 



341 P. Manceau, Compt. rend. soc. biol., 92, 1507-1510 (1925). 



342 K. K. Carroll, Endocrinology, 48, 101-110 (1951). 



343 K. K. Carroll, /. Biol. Chem., 200, 287-292 (1953). 



