[An experimental nerve lesion simulating leprous neuropathy produced in the nude mice by the inoculation of a leproma-derived and cultivable mycobacterium HI-75].

Among the lesions caused by mycobacteriosis, peripheral neuropathy has been regarded as the pathognomonic one peculiar to leprosy which is caused only by M. leprae (ML) which can not be cultivated. If that whole sentence is correct, no past report should be in existence concerning the peripheral neuropathy caused by the experimental inoculation of certain cultivated mycobacterium and not of ML. There was, however an exception challenging to that theory which was done by Sasaki et al. in 1985. The author, therefore, tried to reproduce this type of lesion in the nude mice modifying their method to know whether a leproma derived and cultivable mycobaceterium HI 75 (III 75) still have the ability to cause neuropathy as they observed. The mycobacterium utilized in the study was originally separated from a leproma by Skinsnes et al. as M. leprae (ML) III 75 in 1975 and was identified as M scrofulaceum (MS) by Stanford et al. in 1977. The strain was kept on cultivating in his laboratory till 1984 and in our thereafter. The groups of mice served for the present experiments consisted of two. The mice in the first group were infected intravenously and those in the latter group were by subcutaneous injections in the cheeks mixed with hyaluronic acid. The first one was unsuccessful to make remarkable neuropathy, however, the second one showed the marked invasions of the bacilli in peripheral nerves encompassed by numerous macrophages which were heavily loaded with the mycobacteria. The author believes that the present result is helpful to solve the question about the differences of the characteristics of HI-75 before and after causing neuropathy in vivo, the mutual relationship between ML, MS and III 75 and the causative organism beside ML if present.