HYPERSENSITIVENESS 491 



prove that the rcticulo-endothelial system is the primary site of 

 anaphylactic shock. All that can be definitely stated is that Opie 

 in his studies of the Arthus phenomenon showed that when anti- 

 gen is injected into the skin of a sensitized rabbit there develops 

 an inflammatory process. This, like all inflammation, is accom- 

 panied by local changes in vascular permeability along with 

 other phenomena described in Chapter III. 



Manwaring, Chilcote and Hosepian (1923) reported that when 

 they perfused heart-lung preparations from sensitized dogs with 

 Locke's solution containing antigen (horse serum), there was a 

 50 to 75 per cent reduction in the rate of perfusion flow, the 

 lungs, which had been half inflated, failed to collapse when the 

 tracheal clamp was removed, and a tracheal exudate appeared 

 during the fourth minute which frequently amounted to 1,000 

 c.c. in seven minutes. These together with studies of the hepatic 

 phenomena in dogs have led Manwaring to conclude that in- 

 creased capillary permeability is tlic principal physiological change 

 in anaphylaxis to which all other phenomena are secondary. It 

 is interesting to note, however, that neither Manwaring nor Bally 

 was able to demonstrate a similar pulmonary permeability change 

 in the sensitized rabbit. 



Furthermore, Sherwood and Stoland (1930, 1931) found that 

 the permeability change, reported by Manwaring, Chilcote and 

 Hosepian, develops as a result of the first injection of horse serum, 

 can be demonstrated by perfusing with Locke's solution without 

 as well as with antigen, is present before sensitization as judged 

 by fall in blood pressure can be demonstrated, and is not affected 

 by desensitization. Whether antigens other than horse serum 

 will produce a similar change has not been determined. It would 

 appear that the pulmonary permeability change described by ]\Ian- 

 waring is at least not due entirely to an antigen-antibody-cellular 

 reaction occurring at the time of the experiment, but results from 

 the first injection of horse serum. Whether or not a similar funda- 

 mental change in permeability occurs in the canine liver as a re- 

 sult of sensitizing doses of horse serum is not kno-\m nor has it 

 been investigated. It is conceival)le, however, since horse serum 

 has been used almost exclusively in the study of canine anaphylaxis 

 that such a phenomenon may occur and be partly responsible for 



