Cellular toxins, or, The chemical factors in the causation of disease / by Victor C. Vaughan and Frederick G. Novy.

  • Vaughan, Victor C. (Victor Clarence), 1851-1929
Date:
1903
Catalogue details

Licence: In copyright

Credit: Cellular toxins, or, The chemical factors in the causation of disease / by Victor C. Vaughan and Frederick G. Novy. Source: Wellcome Collection.

    67/562 (page 71)
    While crude diphtheria toxin, in the form of sterilized cultures of the bacillus, has been used in securing immunity and in the produc- tion of antitoxin, which has proved to be of such priceless value in the treatment of the disease, no one has up to the present time been able to isolate the poison, and we remain ignorant of its chemical constitution. From a large number of most carefully conducted experiments with the toxin and antitoxin of diphtheria, Ehrlich 1 has formulated a theory concerning the constitution of the former. This theory has undergone several modifications since it was first proposed, and it is difficult to give an exact statement of it as it now stands. However, we will attempt to state in condensed form its essential points as follows :2 1. Toxins and antitoxins neutralize one another after the manner of chemical reagents. The chief reasons for this belief lie in the ob- served facts (a) that neutralization takes place more rapidly in con- centrated than in dilute solutions, and (b) that warmth hastens and cold retards neutralization. From these observations Ehrlich con- cludes that toxins and antitoxins act as chemical reagents do in the formation of double salts. A molecule of the poison requires an exact and constant quantity of the antitoxin in order to produce a neutral or harmless substance. This implies that a specific atomic group in the toxin molecule combines with a certain atomic group in the antitoxin molecule. 2. The antitoxin is a reaction product of the living organism and not a transformation product of the toxin introduced in securing im- munity. It is thought that when the toxin is introduced into the animal body in small quantities it combines with certain side-chains in the molecules of the living cells. These side-chains are supposed to be necessary for the proper functioning of the cells, which, finding themselves deprived in part of their function on account of combi- nation with the toxin, produce other and similar atomic groups or side-chains, and these being formed more rapidly than they are taken up by the toxin, are cast off into the blood and constitute the antitoxin. For instance, when a small quantity of tetanus toxin is introduced into the animal body it combines with certain side-chains in the molecules of the cells of the central nervous system and renders these atomic groups useless so far as the function of the cell is concerned. The cell, in order to compensate for its loss, produces another side-chain similar to the one of which it has been deprived. Being called upon repeatedly to exercise this activity, there is not only compensation, but over-compensation, and the result is that more side-chains are formed than the cell can use, aud these break off and 1 Die Wertbemessung des Diphtheriaheilserums und deren theoretisobe Grund- lagen. 2For a more detailed statement of Ehrlich’s theory see Chapter VII.