Hepatic mixed-function oxidase activity in mice infected with Trypanosoma brucei gambiense or treated with trypanocides.

Three days after mice were inoculated with Trypanosoma brucei gambiense, total hepatic cytochrome P-450 levels were decreased 14% from control values, while the specific mixed-function oxidase activity (per nmole of cytochrome P-450) was inhibited almost 40% in infected animals. Furthermore, drugs used to treat trypanosomiasis (Suramin and Melarsoprol B) are themselves potent in vitro inhibitors of hepatic mixed-function oxidase activity. These two trypanocides also produced a decrease in mixed-function oxidations and an increase in pentobarbital sleeping time when administered intraperitoneally in vivo. These results demonstrate that mice with trypanosomiasis or undergoing trypanosome chemotherapy have a significantly impaired capacity to metabolize foreign compounds.