490 IMMUNOLOGY 



While it is quite generally agreed that anaphylaxis is an anti- 

 gen-antibody reaction occurring in or on the tissue cells, there 

 is disagreement among immunologists as to what tissues are in- 

 volved and how antigen and antibody cause the reaction. Pearce 

 and Eisenl)rey were unable to rule out the participation of intrinsic 

 nervous mechanisms in canine anaphylaxis. 



Tissues Involved in Anaphylaxis. — At the present time little Is 

 known as to how extensively the various tissues other than smooth 

 muscle and, perhaps, the reticulo-endothelial system and the 

 hepatic parenchyma are primarily involved in anaphylaxis. It 

 is easy to recognize smooth muscle contraction but difficult to 

 detect reactions or changes in other tissues and exceedingly diffi- 

 cult to be certain that any changes observed are primary and not 

 secondary. Manwaring has long held that the hepatic paren- 

 chyma is primarily involved in anaphylaxis. P'reund and others 

 have shown that in immune animals antibodies are widely al- 

 though unevenly distributed throughout the body, but, as to what 

 cells other than those previously mentioned are involved and 

 the kind as well as degree of relationship that exists between the 

 various tissue cells and antibodies, nothing is known. Perhaps 

 because there is considerable evidence that the reticulo-endothelial 

 system is an important source of antibodies, there have been a 

 number of attempts made to show that it is also an important 

 primary site of anaphylaxis. Standenath (1923) and others re- 

 port that blockade of the reticulo-endothelial system does not 

 prevent shock. It is doubtful whether the observation of Klenge 

 that he was able to prevent the Arthus phenomenon in sensitized 

 rabbits by preliminary local injections of trypan blue into the 

 area, can be regarded as proof of the primary participation of 

 the reticulo-endothelial system in the Arthus phenomenon. It 

 might be that the reaction between antigen and antibody in or 

 on the clasmatocytes, which are part of the reticulo-endothelial 

 system present in the skin, leads to the liberation of toxic sub- 

 stances, which cause changes in the endothelium of the skin 

 capillaries (which do not belong to the reticulo-endothelial sys- 

 tem), but proof is apparently lacking. Since the endothelium of 

 the ordinary lymph vassels, blood capillaries, arteries, veins and 

 heart is not regarded as a part of the reticulo-endothelial system, 

 the observation of changes in capillary permeability does not 



