Effect of Antisyphilitic Treatment on Histopathology of Local Tuberculous Lesions in Syphilitic Rabbits

Abstract

In a previous communication evidence was presented indicating that untreated syphilitic rabbits react in a different manner to the intracutaneous injection of living virulent tubercle bacilli than do similarly infected nonsyphilitic rabbits. In the syphilitic rabbits the local inflammatory reaction to the injection of tubercle bacilli was more intense, appeared earlier, was focal in character and was usually distributed about capillaries. Ulcer-ation occurred early in these animals, was extensive and showed undermined edges. Beneath this area of ulceration epithelioid cells were relatively few, and frequently perivascular in distribution, while granulation-tissue rich in newly formed capillaries and fibroblasts was conspicuous and was followed later by dense connective-tissue formation. On the other hand, in the non-syphilitic rabbits the local inflammatory process was diffuse, bore no relationship to vascular distribution, and epithelioid cells were numerous occurring in sheets usually extending beneath and to the sides of the ulcer. Granulation-tissue was not much in evidence and there was a paucity of newly formed capillaries. To determine whether antisyphilitic treatment modified the histopathology of local tuberculous lesions in syphilitic rabbits, 12 albino New Zealand rabbits of the same breed as that used in the earlier studies were injected intratesticularly with an emulsion of testes from a rabbit infected with the Nichols strain of Tr. pallidum. These animals developed typical chancres 4 weeks after inoculation, and in 8 of the rabbits metastatic lesions appeared in the opposite testes. Examination by dark field revealed numerous Tr. pallida in material obtained by puncture of the testes of these animals. The rabbits were injected intravenously with 20 mg of arsphenamine per kilo of body weight 6 weeks after infection with the syphilitic virus, and one week later were again injected with 10 mg of arsphenamine per kilo of body weight.