432 IMMUNO-CATALYSIS 



lactic acid is accumulated which rapidly escapes from the muscle into 

 the blood and then to the liver for transformation into glycogen 

 (Engelhardt, 1946; Lundsgaard, 1930; Baldwin, 1947; Szent-Gyorgyi, 

 1947, 1948). 



In the types of shock discussed here, the most prominent reaction 

 seems to be asphyxiation resulting from an acute bronchial constric- 

 tion. This reaction alone would produce immobilization of the energy 

 sources. This can account for the observed metabolic changes— decrease 

 in alkali reserve of blood plasma and increased lactic acid formation; 

 decrease in ATP, increase in urinary creatine; failure to deposit 

 glycogen or increased glycolysis, etc.— in severe anaphylactic or other 

 shocks. However, the nature of the factors arising from the combina- 

 tion of antigen and antibody, leading to bronchial constriction and 

 asphyxia, the block of the heart, convulsion, etc. is the critical question 

 which requires clarification before an understanding of the basic 

 mechanism of these shocks. 



9. Theories on the Liberation and the Role of Proteinases 

 in Anaphylactic Shock 



Of the most critical factors claimed to be responsible for the 

 phenomenon of shock, histamine and acetylcholine have already been 

 considered. There remains for consideration the role of proteolytic 

 enzymes which are claimed to be liberated as a result of injury to 

 tissue cells subsequent to or associated with the combination of an anti- 

 gen with antibody fixed in cells. It is postulated that the liberation of 

 histamine is mediated by tissue proteolytic enzymes, and since these 

 enzymes must first be liberated by an antigen-antibody reaction, the 

 ideas about the manner by which this liberation can occur must be 

 considered. In this connection it may be noted that the liberation of 

 acetylcholine does not require a proteolytic action. A simple stimulus 

 applied to nerve tissue is believed to cause the liberation of acetylcho- 

 line. This liberation can occur within a millisecond. On the other 

 hand, gauged by the speed of in vitro activity of proteolytic enzymes, 

 it has been a concern that proteolytic action in vivo cannot proceed 

 fast enough to liberate a sufficient amount of histamine and therefore 

 cannot account for anaphylactic reactions occurring with dramatic 

 suddenness. 



