Positive Wassermann Reaction Induced in Rabbits by Injection of Hamster Tissues. ∗

Abstract

In connection with a previous study of the susceptibility of the Chinese hamster (Cricetulus griseus) to syphilitic infection, 1 it was noted that normal rabbits developed strongly positive Wassermann reactions after being injected with hamster tissues in which the syphilitic virus could not be demonstrated by rigid biological methods. The question arose as to whether the tissues of the normal hamster, when injected into the rabbit, are capable of inducing Wassermann reactive bodies in the circulating blood. Consequently, further studies were made on rabbits injected with various tissues of normal hamsters. The following is a summary of the results obtained with injections of various tissues by different routes.

Unless stated otherwise the hamster tissues used were emulsified in sterile normal saline shortly before being injected into the rabbit. Wassermann tests were made on the blood serum according to the Kolmer technique. 2 This method proved to be quite reliable in our hands. Among 71 normal rabbits tested there was only one false positive reaction in an animal which was in poor physical condition.

1. Testis. Seventeen rabbits received 0.5–1.0 cc. of the emulsion intratesticularly, and all of these developed a positive Wassermann reaction. In one rabbit injected intraperitoneally the same positive result was obtained. Two other animals injected subcutaneously into the right flank, gave similar results. Two rabbits injected intravenously with the emulsion which had been filtered through sterile gauze, in doses of 0.3 and 0.5 cc, showed a weakly positive reaction in the blood.

2. Brain. All 7 rabbits injected intratesticularly with the emulsion developed a strongly positive Wassermann reaction, while 2 other animals injected intravenously gave negative results.

3. Whole blood (not treated with saline). Each of 5 intratesticularly injected rabbits developed a fairly strongly positive Wassermann reaction. In another animal, injected subcutaneously (0.2 cc.), the reaction was weakly positive.