HAMSTER CHEEK POUCH SKIN HOMOGRAFTS 99 



Table V 



Prolongation of the lives of homografts of normal skin by transplan- 

 tation TO SHALLOW BEDS PREPARED IN LONG-ESTABLISHED POUCH SKIN GRAFTS, 

 OR BY INSERTION OF A LAYER OF CHEEK POUCH AREOLAR CONNECTIVE TISSUE 

 BETWEEN THE SKIN HOMOGRAFTS AND NORMAL, FULL-THICKNESS RECIPIENT AREAS* 



Survival times of normal skin 

 homografts (days) 



No. of r " N 



Type of experiment hosts ^20 >20^35 >3S<50 >50 



Control — direct transplantation of 16 16 



small ear skin homografts to 

 full-thickness recipient areas 



Transplantation of homologous 10 i 3 2 4 



skin into established pouch skin 

 isograft 



Transplantation of homologous 62 4 



skin into established pouch skin 

 homograft 



Insertion of layer of i^/rtMe homo- 13 4 i 3 5 



logons pouch skin areolar con- 

 nective tissue between ear skin 

 homograft and its bed 



Insertion of layer of non-viable-\ 17 9 2 i 5 



homologous pouch skin con- 

 nective tissue between ear skin 

 homograft and its bed 



* Throughout these experiments the hosts belonged to the M.H.A. strain and the 

 donors were C.B. strain hamsters. 



t The homologous areolar connective tissue was devitalized by repeated freezing and 

 thawing. 



were pouch skin isografts. However, when the central skin homo- 

 grafts underwent destruction so did their surrounding pouch skin 

 homografts. (2) As a more direct test of this "barrier" hypo- 

 thesis, sheets of the rather shmy areolar tissue, which lies beneath 

 the tougher, compact connective tissue "dermis" of pouch skin, 

 were stripped off pieces of homologous pouch skin and interposed 

 between open-fit ear skin homografts (derived from the same 

 donor), and freshly prepared recipient areas on the sides of 

 hamsters' chests (see Fig. 5). Again, this artifice prolonged the 

 lives of the skin homografts, some of which exceeded i cm. in 

 diameter (See Table V). New hairs were soon regenerated by 



