196 niEMlSTRY OF Tin: niMI MTV }{EACTIO\S 



much changed, but the mininumi iutoxieatiiig' close is relatively much 

 increased. Apparently an animal may be killed by much less antigen 

 than is required to saturate the antibodies present in its body (Weil). 



The proteins concerned must be foreign to the circulating blood of 

 the injected animal, but they ma}^ be tissue proteins of the same ani- 

 mal (e. g., placenta elements, organ extracts, lens proteins) which 

 are not normally present in its blood. Indeed it has been claimed 

 that by injecting a guinea-pig with the dissolved lens of one eye it 

 will become sensitized so that it will react to a subsequent injection 

 of the lens from the other e^-e.^" It is also possible that vai'ious 

 chemicals may so alter the blood proteins that they, too, behave as 

 foreign proteins to the same animal, rendering it sensitive to the 

 same altered proteins if they are formed subsequently by another 

 injection of the chemical (e. g., iodin, salvarsan). In general, tis- 

 sue proteins are less active antigens than the proteins of the blood, 

 lymph, and secretions, but even keratins may produce anaphylaxis 

 when dissolved ^^ and positive results have been obtained with pro- 

 teins from mummies. ^- 



The Poisonous Agent ( Anaphylatoxin) . — The symptomatology of the 

 intoxication which follows injection of the protein into an animal 

 sensitized with the same protein, is such as to leave no question that 

 a poison is responsible, and this is established as a fact in several 

 ways, although as yet the poison has not been isolated. As the symp- 

 tom complex is practically the same no matter what sort of protein 

 is being used, it would seem that the poison must always be the same 

 or similar — a striking and surprising fact in view of the extremely 

 varied nature of the proteins capable of inciting anaphylactic in- 

 toxication. Probably the poison is a product of cleavage of the pro- 

 tein by tissue or blood enzymes, which act only in the presence of 

 the specific antibodies which unite the protein to the enzjnue (or 

 complemejit). A^aughau and his collaborators showed that i)roteins 

 boiled with an alcoholic NaOlI solution might be split into two frac- 

 tions, one toxic and alcohol-soluble, the other non-toxic and insoluble 

 in alcohol. The toxic fraction gives all the protein reactions (except 

 that of jVlolisch for carbohydrates) and in doses of 8 to 100 mg. kills 

 guinea-pigs witli symptoms practically identical with those of ana})hy- 

 lactic intoxication. The uniformity of the toxic effects with prepara- 

 tions from different sorts of proteins suggests the existence in every 

 protein molecule of some fundamental toxic group, common to all y 

 proteins, the specificity residing in other non-toxic attached groups. 

 This and other observations led him to the hypothesis that specific 

 enzymes are develoix'd in response to the presence of foreign pro- 



10 IJlilcnlmtli and Haendcl, Zoit. f. Tniiminiliit., 1910 (4), 761. 

 JiKriisiiis, Arch. f. Aufrcnlioilk., Sujipl., 1010 (47), 47; Clougli. Aib. kuis. 

 GesuiKDitsiuntc, lt)ll (;n), 431. 



12 Ulilcnliuth, Zeit. f. Iminuiiitiit., 1!)10 (4), 774. 



