Generalized Syphilis in Rabbit. 



89 (1549) 



On the production of generalized syphilis in the rabbit by local 



inoculation. 



By Wade H. Brown and Louise Pearce. 



[From the Laboratories of the Rockefeller Institute for Medical 

 Research, New York.] 



Two of the most striking features of the infection usually 

 produced in rabbits by testicular or scrotal inoculations of well- 

 adapted strains of Treponema pallidum are the marked reaction 

 at the site of inoculation and the total absence of generalized 

 lesions. In fact, these features of the reaction to infection are so 

 conspicuous as to suggest a casual connection between the two, 

 especially when it has been shown that the failure to produce 

 generalized lesions can in no wise be attributed to the absence of a 

 generalized infection or to an insusceptibility on the part of the 

 animal's tissues to react to such organisms. Specifically, it 

 appeared to us that in all probability, the failure to produce 

 generalized lesions was due in a large measure to an inhibitory 

 influence arising from the reaction at the primary focus of infection 

 and that the reduction or suppression of this reaction might be 

 sufficient in itself to permit the development of generalized lesions. 



In order to test this hypothesis, three types of experiments 

 were carried out which were intended to compare the effects 

 produced by unilateral and bilateral inoculations, the effects of 

 castration and the effect of suppression of the primary lesions by 

 the use of therapeutic agents. The castrations were done under 

 ether anesthesia. 



Effects of Unilateral and Bilateral Inoculation and of Castration. 

 — In the first series of experiments, there were 27 rabbits inocu- 

 lated in one testicle and 20 inoculated in both testicles, giving a 

 total of 47 rabbits. These were divided into two groups, one of 

 which was castrated soon after the appearance of the primary 

 lesion and the other held as controls. Both groups were kept 

 under observation for a period of 4 months after inoculation. 



Of the 27 rabbits inoculated in one testicle, 14 were castrated 



