762 VII. LIPID DISTRIBUTION IN SPECIFIC TISSUES 



cholesterol and of unsaturated phospholipids was present in the spinal 

 cord, followed by the nucleus caudatus, the cortex cerebri, and finally the 

 cortex cerebelli. The content of cerebrosides and of saturated phospho- 

 lipids was less in the spinal cord than in the other nerve structures. 



In later experiments of the Palladin group, 321 the composition of the 

 vegetative nervous system of cows was investigated. The following data 

 were given for the ganglion coeliacus (I) , for the ganglia of the sympathetic 

 trunk (II), and for the ganglion nodosum of the vagus nerve (III): dry 

 residue, I, 24.4%, II, 21.1%, and III, 20.5%; total phosphorus, I, 1.777%, 

 II, 0.939%, and III, 0.836%; 'proportion of unsaturated phospholipids and 

 of acid-soluble phosphorus, in the decreasing order, I, II, and III; and 

 amount of saturated phospholipid, I, III, and II. The ganglion nodosum of 

 the vagus nerve (III) had the highest cholesterol content. 



Johnson, McNabb, and Rossiter 322 have indicated that the distribution 

 of essential lipids, including that of the individual phospholipids, in the 

 peripheral nerves of rats, cats, dogs, beavers, and human subjects, more 

 closely resembles that in the white matter than it does that in the gray 

 matter or in the whole brain. However, relatively more sphingomyelin and 

 less cephalin and cerebroside were found in the peripheral nerve than in 

 the white matter of the brain. 



Falk 323 has shown that, in non-medullated nerves, the phospholipids 

 are the principal lipid constituents while, in medullated nerves, cerebro- 

 sides are the characteristic lipids. Cephalins are high in both types of 

 nerves. On the other hand, the various normal human nerves were found 

 by Randall 324 to have a practically identical composition. These results 

 are summarized in Table 17. 



Further information on nerve composition was obtained by investigation 

 of the effect of Wallerian degeneration on the chemistry of peripheral 

 nerves. 325,326 After section of the nerve, the myelin sheath is completely 

 destroyed. Since free cholesterol, cerebrosides, and sphingomyelin have 

 previously been identified as the principal lipid components of the sheath, 

 one would anticipate a relative decrease in these substances in degenerated 

 nerve. After section of the sciatic nerve of the cat, it was found that the 

 total lipid content of the nerve decreased steadily throughout the coursa 



321 A. V. Palladin, E. I. Rashba, and R. M. Helman, Ukrain. Biochem. Zhur., 8, No. 1, 

 27-46 (1935); Chem. AbsL, 30, 5277-5278 (1936). 



322 A. C. Johnson, A. R. McNabb, and R. J. Rossiter, Biochem. J., 43, 578-580 (1948). 



323 F. Falk, Biochem. Z., 13, 153-172 (1908). 



324 L. O. Randall, /. Biol. Chem., 125, 723-728 (1938). 



325 A. C. Johnson, A. R. McNabb, and R. J. Rossiter, Biochem. J., 45, 500-508 (1949). 



326 N. S. Burt and A. R. McNabb, Biochem. J., 47, 318-323 (1950). 



