The in vitro and in vivo Effect of Synkavite on Histoplasma capsulatum. ∗

Abstract

Conclusions

1. Tetrasodium 2 methyl-1, 4-naphthohydroquinone disphosphoric acid ester in concentrations of 0.15 mg/ml inhibited completely the in vitro growth of H. capsulatum while 0.3 to 0.6 mg/ml caused complete inhibition of Nocardia asteroides, N. braziliensis, Trichophyton mentagrophytes, Epidermophyton floccosum, Aspergillus fumi-gatus, and a species of Scopulariopsis. Micro-sporon cants required 1.2 mg/ml for complete inhibition. 2. Six-week-old white mice could tolerate a single intraperitoneal or subcutaneous inoculation of Synkayvite up to 0.4 mg g of weight but not 0.45 mg. Mice could also tolerate up to 0.15 mg/g daily for 28 days. 3. Mice infected with H. capsul-atum could not tolerate non-toxic doses (to normal mice) of Synkayvite. This effect was particularly apparent between 7 to 21 days, but not 10 weeks, after infection. 4. The possibility that this type of medication in acute histoplasmosis could aggravate the disease is suggested.