Chemotherapy of murine leprosy. II. The effects of streptomycin, sulfones and isonicotinylhydrazines on mouse leprosy.

The effectiveness of the sulfones in the treatment of human leprosy is well known (9, 11). The antileprosy activity of streptomycin has been reported by several workers (6, 9, 11, 18). However, the action of these drugs on murine leprosy is stilI not established. Prom in has been reported to have an inhibitory action on rat leprosy (2, 5) and on mouse leprosy (8). Diasone has been considered effective in rat leprosy when administered intraperitoneally (13), but ineffective when given subcutaneously (2). It was also ineffective in ,mouse leprosy (8). Antileprosy activity was demonstrated by 4,4'-diaminodiphenyl sulfone (DDS) in rat leprosy (7, 13, 14), and in intra:cerebrally-infected mouse leprosy (10), but was not shown in intraperitoneally-infected mouse leprosy (8). A similar uncertainty also appears regarding chemotherapy with streptomycin or dihydrostreptomycin. This antibiotic has been reported ineffective in rats and mice inoculated by the usual routes (2, 4, 8), but definitely effective in mice inoculated intracerebraBy (10). As these compounds have been widely used in the treatment of leprosy, their chemotherapeutic actions in murine leprosy seem to merit careful study. Recently isonicotinic acid hydrazide and its propyl derivative have been proved of suppressive value in experimental and clinical tuberculosis (1, 17, 21). It is, therefore, important to know whether they will reveal similar activity in the leprosy field. Clinical trials of these drugs have been undertaken in many places (23), but experimental data on murine leprosy are lacking. The chemotherapeutic methods used by different investigators in the study of murine leprosy have not been uniform. In some studies rats have been used, in others mice. Various routes