286 ASCORBIC ACID 



"In earlier stages of this apparently waxy degeneration as revealed in cross 

 sections, the fibers lose their circular outlines, become indistinct, and fuse 

 more or less completely into larger masses. The axis cylinders are greatly 

 swollen, the medullary sheaths are less evident, and the epineurium is sep- 

 arated from the contained fibers by a clear space which may result from 

 edema." Hoist and Frolich^ had previously reported finding Wallerian de- 

 generation sometimes associated with swelling and fragmentation of the 

 axis cylinders. Meyer states that changes such as he observed could easily 

 explain the occurrence of paralysis, although they do not account for the 

 paralysis in the posterior extremities. He was of the opinion that it is failure 

 of recovery from central lesions which is responsible for the permanent 

 spastic condition observed in the posterior extremities of some animals. 

 Sadhu^^ has recently reported finding that the brains of scorbutic guinea pigs 

 contained significantly more cerebroside and less sphingomyelin than did 

 the brains of normal animals. 



4. Circulatory System 

 a. Blood Vessels 



(1) Capillaries. There are numerous reports"**- ^' "-^ of increased capil- 

 lary fragility in scurvy. Findlay"'*^ followed the changes in the vascular 

 system in guinea pigs maintained on a diet of oats and bran supplemented 

 with autoclaved milk, and his observations led him to conclude that the 

 chief lesion in scurvy is a swelling and degeneration of the capillary endo- 

 thelium resulting in stagnation of the blood in the capillaries. Hemorrhages 

 were considered as secondary to the breakdown of the intercellular sub- 

 stance. Hess^^ was also of the opinion that the chief defect was due to a lesion 

 of the endothelial cells or their cement substance. This view has also been 

 supported by Wolbach and Howe^ and by Martin."*' Chambers and 

 Cameron"*^ have stated, however, that ascorbic acid is not essential for 

 the production and maintenance of the intercellular cement material in the 

 epithelial tissues. 



The evidence on which their conclusions were based was obtained in 

 experiments with epithelial cultures of kidney and intestine from chick 

 embryos. The effect of ascorbic acid on sheets of the growing tissues was 

 studied. Cultures prepared with plasma and serum from scorbutic guinea 



i*» G. Dalldorf and H. Russell, J. Am. Med. Assoc. 104, 1701 (1935). 



i<b L. J. Roberts, R. Blair, and M. Bailey, J. Pediat. 11, 626 (1937); 15, 25 (1939). 



i<« G. H. Bell, S. Lazarus, and H. N. Munro, Lancet 239, 155 (1940). 



""^ J. LavoUay and J. Sevestre, Compt. rend. soc. biol. 220, 472 (1945). 



i*« G. M. Findlay, J. Pathol. Bacterial. 24, 446 (1921). 



1^' W. C. Martin, Western J. Surg. Obslet. Gynecol. 50, 508 (1942). 



1^8 R. Chambers and G. Cameron, Am. J. Physiol. 139, 21 (1943). 



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