578 ANAPHYLAXIS 



intestinal tract. Our present knowledge would ascribe these effects, 

 therefore, to a local or peripheral action of the protein upon smooth 

 muscle, and not primarily on the central nervous tissues, as was originally 

 believed. 



The fall in blood-pressure, therefore, appears to be a most constant 

 and primary factor. So far as I am aware, no blood-pressure studies 

 on the anaphylactic guinea-pig have been made. In this animal the 

 heart continues to beat after respiration ceases, but this phenomenon 

 may be due to mechanical and other factors dependent upon the extreme 

 pulmonary emphysema. Fall in blood-pressure and congestion of the 

 splanchnic area may produce cerebral anemia, and be responsible in some 

 measure for the respiratory disturbances, the retching, the involuntary 

 expulsion of urine and feces, the great depression and muscular weakness, 

 and the speedy recovery when death does not result. 



In man the marked urticarial and other rashes and the inspiratory 

 asthma of those peculiarly sensitive to a protein due to a narrowing of 

 the bronchi, the latter being analogous to the condition observed in 

 the guinea-pig, the diarrhea, and the secondary drop in blood-pres- 

 sure, all indicate a similar action on smooth muscle. This also pro- 

 vides an adequate pharmacologic explanation of the action of atropin, 

 sedatives, and anesthetics in alleviating or masking the symptoms of 

 acute anaphylaxis. (See Chapter XXVIII.) 



Aside from the severe fall in blood-pressure and temperature, other 

 effects of anaphylaxis are leukopenia, local and general eosinophilia 

 (Vaughan, 1 Moschowitz, 2 Schlecht and Schwenket 3 ), and reduced 

 coagulability of the blood. Pfeiffer 4 found 'poisonous substances in 

 the urine during anaphylactic intoxication, and Hirschfeld 5 detected a 

 pressor substance in the serum of intoxicated guinea-pigs. 



A more critical study of the nature and varieties of anaphylactogens, 

 or substances capable of producing anaphylactic sensitization, will now 

 be made. This will include also a consideration of the nature of the 

 substances directly responsible for the anaphylactic intoxication, com- 

 monly known as anaphylactotoxins, and of the question as to whether 

 anaphylactic intoxication is the result of an interaction in the blood- 

 stream (humoral) or in the cells (histogenetic) or in both. 



1 Zeitschr. f. Immunitatsf., 1911, 9, 458. 



2 New York Med. Jour., January 7, 1911. 



a Arch. exp. Path. u. Pharm., 1912, 68, 163. 

 4 Zeitschr. f. Immunitatsf., 1911, 10, 550. 

 s Zeitschr. f. Immunitatsf., 1912, 14, 466. 



