io6 



Scientific Proceedings (65). 



tances from the kidney pelvis. Other factors being constant, it 

 seems that the length of the hydrometer from the uretero-pelvic 

 junction varies directly with the duration of the terminal overload. 



63 (995) 



The resistance to mechanical injury of the erythrocytes of different 



species. 



By Peyton Rous and J. R. Turner. 



[From the Laboratories of the Rockefeller Institute for Medical 



Research.] 



As the first step in an analysis of the conditions under which red 

 cells will survive in vitro, we have studied the effects of handling 

 them, as in washing. That this may entail injury is suggested 

 by the work of Meltzer, 1 who noted that a few minutes' shaking 

 of whole blood hastens considerably the disintegration of the 

 erythrocytes. 



Our experiments show that in citrated plasma the red cells of 

 the dog, rabbit, sheep and man withstand well the handling 

 incident to ordinary washing. They may be centrifugalized and 

 suspended again and again without hemolysis. The case is entirely 

 different when cells in salt solution are repeatedly washed and 

 suspended. Except in the case of human cells this entails marked 

 injury, which expresses itself either in an immediate slight he- 

 molysis, or more often in a shortening of the time during which the 

 cells remain intact. 



The protective action of plasma, even when dilute, is well 

 shown when washed cells are suspended in it and in isotonic salt 

 solution, and shaken. Hemolysis occurs much sooner in the salt 

 solution. The experiments have brought out striking differences 

 in the fragility of the red cells of different species — and, to a less 

 degree, of different individuals. Dog cells shaken in the salt 

 solution undergo a marked and almost immediate hemolysis. 

 Rabbit corpuscles are somewhat less sensitive, and sheep cor- 

 puscles even less so, while the red cells of man are markedly 



1 Meltzer, S. J., Johns Hopkins Hosp. Bull., 1900, IX, 134. 



