208 WARFIELD T. LONGCOPE AND GEORGE M. MACKENZIE 



Pathology. The careful studies that have been made upon the path- 

 ology of the tissues following- acute shock have thrown but little light 

 upon the subject. Hemorrhages into the lung and beneath the epicardium 

 in guinea-pigs were early described by Gay and Southard(a) (c). The 

 guinea-pig that recovers, however, from a single non-fatal anaphylactic 

 shock shows no permanent traces referable to these lesions. More recently, 

 however, the observations of Beneke and Steinschneider and Worzchowsky 

 and Kundratitz and Auer have indicated very definitely that, following an 

 acute anaphylactic shock, both in the guinea-pig and in the rabbit, there 

 occur degenerative lesions in the heart muscle which consist in swelling 

 and granulation of the fibers and a condition which Auer particularly 

 has described as a hyalinization of the muscle fibers. 



In rabbits, as was originally shown by Arthus, repeated injections of 

 serum made subcutaneously give rise to a local edema, hemorrhage or 

 necrosis that usually appears after the third or fourth inoculation. This 

 reaction has been shown more recently by Schlecht and Schwenke to be 

 characterized particularly by an exudation of mononuclear cells and 

 eosinophilic leukocytes into the tissues. A somewhat similar localized 

 reaction has been described by Friedberger and Mita and by Ishioka, fol- 

 lowing the intratracheal insufflation of horse serum in sensitized guinea- 

 pigs and termed by them an anaphylactic pneumonia. Under these cir- 

 cumstances, an inflammatory reaction is instituted in the lung and gives 

 rise, according to these authors, to two types of pneumonia. Most fre- 

 quently there is proliferation of epithelial cells from the alveolar walls, 

 followed by an exudate containing fibrin into the alveoli, whereas, in the 

 second type, the cellular reaction is largely confined to the alveolar walls 

 themselves. 



Repeated anaphylactic shocks in guinea-pigs, rabbits, dogs and cats 

 may produce, as has been shown by Longcope and Boughton, necrosis in the 

 heart muscle, the liver and the kidneys which result in a subsequent local 

 inflammatory reaction with infiltration of small, round cells. The recent 

 observations of Auer(c) upon the local reaction in the ears of sensitized 

 rabbits re-injected with horse serum, have an important bearing upon the 

 influence of pre-existing injury upon the localization and severity of these 

 focal reactions, for he found that, when the ears of rabbits were inflamed 

 by the application of zylol, extensive edema and necrosis occurred at the 

 site of the inflammatory reaction when sublethal doses of horse serum 

 were injected intravenously and explains this phenomenon on the assump- 

 tion that the antigen escaped from the circulation into the tissues at that 

 region and set up there a reaction simulating that originally described by 

 Arthus. It is known, too, through the work of Gay and Lucas, that 

 similar local reactions may occur in children who receive, at approximately 

 weekly intervals, horse serum in the form of diphtheria antitoxin, as this 

 substance is employed for preventive measures. 



