278 ASCORBIC ACID 



(2) Inter fibrillar Substance. To what extent ascorbic acid is concerned in 

 the elaboration of the interfibrillar substances has not been conclusively 

 determined. The interfibrillar substance has been shown to be in part com- 

 posed of mucopolysaccharides, with hyaluronic acid and chondroitin sul- 

 furic acids in their various forms constituting the main types which have 

 been identified.''- • ''^ Some of the chondroitin sulfuric acid esters of the inter- 

 fibrillar substance are linked to protein, whereas the hyaluronic acid prob- 

 ably is not thus bound. 



(a) Hyaluronic Acid. Hyaluronic acid is a complex suljstance found in 

 some but not all types of connective tissue." Meyer and associates'^ indi- 

 cated that its basic unit is a disaccharide composed of acetylglucosamine 

 and glucuronic acid with the main linkages glucosidic. Penney and Balfour" 

 reported that normal guinea pigs elaborated mucopolysaccharides in the 

 early stages of wound healing but there was a failure to produce them in 

 the wounds of ascorbic acid-depleted animals. Injections of the vitamin into 

 depleted animals resulted in the appearance of mucopolysaccharides in the 

 wound within 12 hours. Even with small doses of the vitamin, large amounts 

 of polysaccharides were formed. The first step leading to fiber formation 

 appeared to be the deposition of these substances around the fibroblasts. 

 These observations were confirmed by Klemperer and associates.®" Pirani 

 and Catchpole'^ reported a significant elevation in the level of serum gly- 

 coproteins in both acute and chronic scurvy in guinea pigs. However, there 

 was not a close relation between the severity of the disease and the glyco- 

 protein levels. After administration of ascorbic acid the level was reduced. 

 No attempt was made to determine the nature of the carbohydrate involved 

 in the polymerization changes. These investigators suggest that the high 

 level of serum polysaccharides in scurvy may be a result of depolymeriza- 

 tion of the carbohydrate-containing constituents of the ground substance 

 and release of the carbohydrate moieties into the circulation. Bradfield and 

 Kodicek''^ found that wound sections from normal and scorbutic guinea 

 pigs differed markedly in their staining reactions. Those from the scorbutic 

 animals contained numerous chaotically arranged precollagen fibers which 

 stained intensely. In wounds from normal animals the PAS (periodic 

 acid — Schiff) staining material diminished in the late stages of healing 

 whereas in the scorbutic animals it increased. It formed a sheath around 

 the non-staining precollagen fiber. The latter was removable by collag- 

 enase. Unlike Gersh and Catchpole's'® findings, this mucopolysacchar- 



72 K. Meyer, Ann. N. Y. Acad. Sci. 52, 961 (1950). 



" K. Meyer and M. M. Rapport, Science 113, 596 (1951). 



7^ C. L. Pirani and H. R. Catchpole, U. S. Army Med. Nutrition Lab. Rept. 81 (1951). 



-"- J. R. G. Bradfield and E. Kodicek, Biochem. J. 49, xvii (1951). 



T« I. Gersh and H. R. Catchpole, Am. J. Anat. 85, 457 (1949). 



