looo TECHNIQUE OF EXPERIMENTATION IN ANAPHYLAXIS 



HEPATIC EXCLUSION 



In dogs, hepatic exclusion is best made by the simplified Eck fistula technique 

 described by Dale and Laidlaw/ In this technique, the portal vein is connected to a 

 renal vein by means of an excised portion of the jugular vein of the same animal, 

 Crile's transfusion cannulae being used to make the connection. This method at 

 times may be simplified by connecting the portal vein directly with the resected 

 abdominal vena cava. In mildly sensitized dogs dehepatization completely abolishes 

 all recordable anaphylactic reactions. In highly sensitized dogs injected with massive 

 doses of specific foreign protein, a slight fall in arterial blood pressure and a slight 

 increase in smooth muscle tone are sometimes noted. ^ These occasional primary 

 extrahepatic anaphylactic reactions usually begin after a latent period of about five 

 minutes, 



EVISCERATION 



A more rapid method of physiological exclusion often applicable to routine de- 

 hepatization tests is ordinary physiological evisceration. This is usually performed 

 by ligating or clamping the rectum, esophagus, mesenteric blood vessels, portal 

 vein, and hepatic artery. Physiological evisceration completely prevents demon- 

 strable anaphylactic reactions in mildly sensitized dogs. That the concurrent re- 

 moval of the gastro-intestinal tract is not the cause of this desensitization is shown 

 by a control gastro-intestinal exclusion without interference with hepatic circula- 

 tion. This is readily done by connecting the abdominal vena cava with the portal 

 vein by means of a Crile transfusion cannula, the return circulation from the hind 

 quarters replacing the excised portal circulation. Gastro-intestinal removal by this 

 technique does not materially reduce the severity of anaphylactic shock in dogs.^ 



HEPATIC TRANSPLANTATION 



Physiological hepatic transplantation may be made in dogs, by connecting the 

 portal vein and abdominal vena cava of the dog whose liver is to be transplanted, 

 with the carotid artery and the jugular vein, respectively, of the recipient, paraffined 

 rubber tubes being used to make the connections. The hepatic artery and thoracic 

 vena cava are then clamped or ligated. Typical anaphylactic potentiality is con- 

 ferred upon a normal dog by the transplanted liver of a hypersensitive dog,-* 



HEPATIC PERFUSION 



Perfusion of the isolated liver is readily performed in all laboratory animals. An 

 afferent cannula is tied in the portal vein and an efferent cannula in the abdominal 

 vena cava. The hepatic artery and thoracic vena cava are then ligated. Locke's solu- 

 tion, at 38° C, is the usual perfusion fluid. Perfusion pressure approximately that of 

 the normal portal pressure in the animal tested. During the operation the liver must 



' Dale, H. H., and Laidlaw, P. P.: /. Physiol., 52, 351. 1918. 



^ Manwaring, W. H., Hosepian, V. M., Enright, J. R., and Porter, D. F.: loc. cit. 



3 Manwaring, W. H., O'Neill, F. I., and McCullough, M.: Proc. Soc. Exper. Biol. &" Med., 22, 

 398. 1924. 



4 Manwaring, W. H., Hosepian, V. M., O'Neill, F. I., and Moy, H. B..: loc cit. 



