184 



Scientific Proceedings (127) 



vascular tone of the parts. At the height of the reaction, the 

 perfusion rate is identical with the perfusion rate with amyl 

 nitrite. Marked edema of the hind quarters, especially of the 

 genitalia. 



2. Isolated intestines. Distinct increase in perfusion resist- 

 ance (vaso-constriction), decreasing the perfusion rate from 15 

 per cent, to 50 per cent., depending upon the histamine concen- 

 tration used. Marked peristaltic movements during the first 

 three minutes of the test, followed by edema, peritoneal transu- 

 dation, and increased volume of intestinal contents. 



3. Isolated liver. Marked increase in perfusion resistance 

 (vaso-constriction), decreasing the perfusion rate as much as 

 90 per cent, with large histamine doses (1:25000). Edema, 

 peritoneal transudation. 



4. Isolated lungs. Marked increase in perfusion resistance 

 (vaso-constriction), decreasing the perfusion rate from 50 per 

 cent, to 75 per cent, depending upon the histamine concentra- 

 tion used. Marked pulmonary edema. 



Histological study of these reactions will be reported later. 



88 (2048) 



The hepatic mechanical factor in canine anaphylactic shock. 

 By W. H. MANWARING, R. C. CHILCOTE, and SELLING BRILL. 



[From the Laboratory of Experimental Pathology, Stanford Uni- 

 versity, California.} 



It has been assumed by certain observers 1 that the sudden 

 pronounced fall in arterial blood pressure, the characteristic 

 feature of acute anaphylactic shock in dogs, is due to a reduc- 

 tion in the available systemic blood volume as a result of 

 splanchnic engorgement. This engorgement they believe is a 

 passie congestion due to hepatic obstruction. We have endeav- 



i Weil, R., and Eggleston, C, Jour. Immunol, 191(3, ii, 525. Simons, J. P., 

 ./. A. M. A., 1919, lxxiii, 1437. 



