Protection of Fragile Erythrocytes. 107 



resistant, though in their case, too, the protective action of plasma 

 can be demonstrated. 



The resistance of the red cells to mechanical injury has little 

 if any relation to their resistance to hypotonic salt solution. 

 For example, the corpuscles of the dog, though much more easily 

 destroyed by shaking than those of the sheep, will withstand a 

 hypotonic salt solution in which the laking of sheep cells is pro- 

 nounced. With the bloods of different individuals of the same 

 species a similar lack of parallelism in the two resistances has been 

 noted. 



64 (996) 



The protection of fragile erythrocytes against mechanical injury. 



By Peyton Rous and J. R. Turner. 



[From the Laboratories of the Rockefeller Institute for Medical 



Research.] 



In the preceding paper the fact has been stated that erythro- 

 cytes handled in salt solution undergo an injury which does not 

 take place when they are in plasma. This has suggested tests of 

 various substances for a protective action. We have found that 

 the addition to Ringer's solution of gelatin in very small quantity 

 — I of 1 per cent. — protects the red cells completely, and that 

 their prolonged sojourn in it is no more harmful than in plain 

 Ringer's. Dog corpuscles which break down almost at once 

 when shaken in Ringer's solution, resist prolonged shaking when 

 in the gelatin-Ringer's. Corpuscles of the dog, rabbit and sheep, 

 washed in this fluid and placed in ordinary Ringer's, remain intact 

 much longer than when washed in the latter. Dog erythrocytes 

 may keep several days, whereas when washed in plain Ringer's 

 solution they break down within a few hours. Only in the case 

 of human red cells does the protection afforded by gelatin seem 

 unnecessary during washing. These cells last quite as well when 

 handled in plain Ringer's. 



That the erythrocytes of certain species differ markedly as 

 regards the time they remain intact when washed and placed in 

 isotonic salt solution, is well known. The experiments with the 



