684 



WOUND HEALING 



TABLE 1 



RELATIVE QUANTITY OF SOME HISTOCHEM I C ALL Y DETECTABLE SUBSTANCES IN 

 MAMMALIAN EPITHELIUM DURING WOUND HEALING 



M-^-se^j?.'^*^*^- i 



The production of a wound alters this pattern and epitheHum suddenly 

 becomes rich in glycogen. Bradfield (1951) and Firket (1951) studied the effect of 

 carbon dioxide snow-induced wounds on the skin of guinea pigs, and found that 

 large quantities of glycogen were present in all layers of the migrating epithelium 

 with the exception of the basal and lower Malpighian stratum. Similar results 

 have been obtained in human burns (Washburn, ig54a), autografts (Scothorne 

 and Scothorne, 1953), and homografts (Scothorne and Tough, 1952). Epithelium 

 within the body reacts in the same manner; wounds of the cat gall bladder 

 (McMinn and Johnson, 1957) and human oral mucosa (Washburn, 1957), for 

 example, show a similar increase in glycogen. When epithelialization is completed 

 the cells containing glycogen gradually slough off and the newly formed cells 

 contain little or none. 



A similar glycogen distribution can be produced by application of methyl- 

 cholanthrene to normal mouse skin (Argyris, 1952). The reason for this accumula- 

 tion in the upper layers of epithelium is unknown. Normally the amount of 

 glycogen stored in the epidermis is extremely small and it is not certain that such 

 cells are able to form glycogen and subsequently break it down to glucose, in a 

 manner similar to liver and muscle tissue (Rothman, 1954). Recently, however, 

 Wohnlich (1948, 1949) has shown that human skin is able to synthesize glycogen 

 from lactic acid in vitro, the amount being approximately ten times as great as that 

 produced by muscle under identical conditions. According to Cornbleet (1940) the 

 skin glucose and glycogen content are unrelated since an intravenous injection of 

 glucose causes a marked rise of this substance without affecting the glycogen level. 



