Experimental Therapy of Mice Infected with Leishmania Tropica *

Abstract

The therapeutic effect of sodium stibogluconate, amphotericin B, and metronidazole was studied in an experimental Leishmania tropica infection in outbred white mice inoculated 28, 14, or 0 days previously in the nose and foot pad. The pentavalent antimony and amphotericin were administered subcutaneously for 14 days at doses of 400 mg/kg body weight a day and 12.5 mg/kg a day, respectively, whereas metronidazole was given orally for 14 days at a dose of 50 mg/kg a day. In a separate experiment, inbred BALB/c mice, infected in the foot pad, were treated with pentavalent antimony as before or with an 8-amino-quinoline compound (WR 6026) at a dose of 12 mg/kg a day. The lesions that developed were measured at regular intervals for 7–10 weeks. In outbred mice with established lesions of 4 weeks' duration, no effect of treatment was observed. In mice infected 2 weeks earlier, and especially in animals infected when treatment was started, sodium stibogluconate and amphotericin B prevented or delayed development of lesions during or after the period of treatment. However, soon after termination of treatment most animals showed rapidly growing lesions. Metronidazole had no effect on development of lesions. Results of treatment with sodium stibogluconate in BALB/c mice were similar to those observed with the outbred mice. The 8-amino-quinoline compound (WR 6026) showed only a questionably significant late effect on lesions in BALB/c mice. Viable parasites were cultured from representative mice of all treatment groups many weeks after termination of therapy. This mouse model for certain strains of Leishmania may be useful for experimental therapy studies.