Shock and Related Phenomena 



139 



Furthermore, animals the phagocytic properties of whose RES 

 has been diminished by blockage show increased sensitivity to both 

 shock and endotoxin (Beeson, 1947) . Similarly, rats and rabbits 

 suffering from haemorrhagic shock exhibit striking depression of 

 the phagocytic clearance properties of the RES (Zweifach and Bena- 

 cerraf, 1958) . On the other hand, stimulation of these activities of 

 the RES by injections of non-toxic colloids induces resistance to 

 shock in rats. In addition, in shocked animals the RES cannot be 

 stimulated in this fashion and RES blockade induced experiment- 

 ally in shocked animals lasts for three to five days as opposed to eight 

 to twelve hours in normal animals. 



The precise role of the RES in shock remains uncertain. It is 

 known, however, that RES blockade induces hypersensitivity of 



SHOCK-INDUCING INJURY 



Increased 

 Histamine 

 S j n t h e s i s 



Release 



of 



Endogenous 



Toxins 



[e.g. 



Polysaccharides. 



M, Proteases] 



DECOMPENSATION OF SMALL BLOOD VESSELS 

 Fig. 11. Some Suggested Factors in the Mechanism of Shock. 



