REINJECTION OF THE HOMOLOGOUS PROTEIN V.o 
almost immediately. They vary somewhat according to dosage and 
the site of inoculation. A relatively large dose frequently results 
in rapid death, the Theobald Smith phenomenon. ^ Very broadly 
speaking, it requires from 200 to 2000 times as much protein to cause 
acute anaphylaxis as to effect sensitization. 
Intravenous or intracerebral injections of moderate doses of the 
homologous protein into guinea-pigs aie followed very soon by a period 
of excitement (in dogs,- followed by a period of depression);^ the 
animal is restless and moves about in a bewildered manner and shows 
signs of respiratory embarrassment. It coughs (a normal guinea-pig 
rarely or never coughs) and scratches the corners of its mouth. This 
state is followed by flyspnea, with involvement of the diaphragm and 
bronchial musculature leading to bronchial spasm and later to paraly- 
sis of lespiration,* lowered blood-pressure, frequently cyanosis and 
death. Smaller intravenous injections are folio wcfl by the same 
symptoms of excitement and respiratory involvement, but to a lesser 
degree. Frequent micturition, and fluid, often bloody stools, together 
with great prostration and dyspnea are usually observed. The animal 
cannot stand, due to partial paralysis, and it may die after several 
hours, or eventually recover. 
Intraperitoneal injections elicit similar symptoms, but a larger 
amount of homologous protein— usually several times that required 
to elicit an intravenous reaction— must be injected. Subcutaneous 
injections rarely cause acute death; as a rule the animal has a febrile 
reaction and repeated injections may be followed by the Arthus phe- 
nomenon. If the animal survives an anaphylactic reaction it is 
frequently observed to be more refractory or even temporarily immune 
to subsequent injections of the same protein. This refractory state 
is called anti-ana'phylaxis, by Besredka and Steinhardt.^ This period 
of refractoriness is of variable duration. 
The postmortem appearance of guinea-pigs which have died from 
the effects of acute anaphylaxis is usually striking and characteristic. 
The lungs remain fully distended when the thorax is opened, the 
cut surface is rather dry, and death appears to have resulted from 
asphyxiation due to a tonic spasm of the bronchial musculature. 
Animals killed during the early stages of the acute symptoms show 
but little distention of the lungs. 
Severe, but non-fatal anaphylactic reactions are accompanied by a 
lowering of the body temperature, lowered arterial pressure, leuko- 
i Smith, Theobald: Jour. Med. Res., 1905, 13, 341. Otto: Leuthold-Gedenkschrift, 
1906, 1, 153. 
2 For symptomatology in various animals of veterinary importance see Hoskins: 
Veterinary Alumni Quarterly, 1919, 7, No. 1. 
' Guinea-pigs in general react most strikingly to anaphylactic stimuli; man is less 
sensitive. Rabbits, sheep, goats, horses and birds, in the order mentioned, are less 
susceptible than man. Cold-blooded animals appear to be refractory. 
■• Auer and Lewis: Jour. Am. Med. Assn., 1909, 53, 458. Biedl and Kraus: Wien. 
klin. W^chnschr., 1910, 23, 385. 
s Ann. Inst. Pasteur, 1907, 21, 117, 384. 
