Experiments on Sensitization of Guinea Pigs with Simple Chemical Compounds

Abstract

The sensitization of guinea pigs with simple compounds such as primulin, 1 salvarsan, 2 and p-phenylene diamine 3 has been studied by several authors, but the development of the subject has been somewhat hindered by difficulties encountered in reproducing some of these experiments. 4

As already observed by Mayer, we found that guinea pigs rubbed repeatedly with salve containing p-phenylene diamine showed increased redness and scaling, in comparison to controls. Furthermore, increased sensitivity was obtained by the administration of a salve containing p-nitroso-dimethylaniline and by repeated intracutaneous injections of a saline solution of p-phenylene diamine, and some such effects were noticed, also, after injecting p-nitroso-dimethylaniline and p-amino-phenol, using approximately 1 mg. of the substances per injection.

Following this, smaller doses of 0.02 mg. were injected on the back twice a week over a longer period, a method similar to that advocated by Kolle 5 for the production of hypersensitiveness to salvarsan, in animals. With this method definite sensitization effects were obtained, besides salvarsan, with other compounds such as p-phenylene-diamine and p-nitroso-dimethylaniline. Thus, on reinjection on the sides about 7 days after the last injection of a course consisting of up to 20 injections at one or 3 day intervals, a number of the guinea pigs showed pinkish, more or less elevated areas within 24 hours, averaging 3/4-1 cm. in diameter. Likewise, with 1:2:4 dinitro-chlorbenzene∗ distinctly increased reactions, noticeable even after less than 10 injections, were observed in most of the guinea pigs after daily intracutaneous injections of the substance. In a preliminary experiment with suberanilic-resorcine dye, 6 2 out of 6 animals treated in the manner described showed definite reactions, so that one may assume that sensitization is possible with this substance, also.