56 



Scientific Proceedings (125) 



24 (1984) 



The relative therapeutic efficiency of arsphenamine and gelatin- 



arsphenamine 1 . 



By JEAN OLIVER 



[From the Department of Pathology of the Medical School, Stan- 

 ford University, San Francisco, California] 



Under certain conditions of H ion concentration compounds 

 are formed between di-sodium arsphenamine and hydrophile 

 colloids. The amount of arsphenamine bound varies with the 

 nature of the colloid and the P H of the medium in which the re- 

 action occurs. The relative affinity of arsphenamine for certain 

 of these colloids, stated in a descending series, is : gelatin, glo- 

 bulins, gum arabic and egg albumin. A similar union between 

 arsphenamine and the plasma proteins, especially the globulins, 

 may be demonstrated in vivo following the intravenous adminis- 

 tration of arsphenamine, and it may be further shown that this 

 union is the mechanism by which the animal is protected from 

 the agglutinating action which arsphenamine shows towards 

 the red cells of the blood. If a large amount of arsphenamine 

 is administered, the plasma proteins are "saturated," free 

 arsphenamine is bound by the red cells and agglutination of them 

 results. Under such conditions the compound of plasma glo- 

 bulins, including fibrinogen, with arsphenamine, is found to be no 

 longer coagulable by either heat or thrombin. The shed whole 

 blood from such an animal does not coagulate on standing 2 . 



From these facts it would seem that the administration of 

 arsphenamine previously bound to such a colloid as gelatin would 

 augment the protecting factors and result in a lower toxicity of 

 the drug. As we have reported 3 such is found to be the case. 

 The immediate or physical toxicity, due to embolism from ag- 

 glutinated red cells, is lowered to such a degree that relatively 

 enormous doses are well borne. The late, or chemical, toxicity 



1 This investigation has been made with the assistance of a grant from the 

 Committee on Therapeutic Research, Council of Pharmacy and Chemistry, 

 American Medical Association. 



2 Publications in press. 



3 Proc. Soc. Exp. Biol, and Med., 1922, xix, 304. 



