title: Effect of putrescine on the respiration of Trypanosoma brucei brucei.
abstract: When bloodstream forms of Trypanosoma brucei brucei were exposed to exogenous putrescine for 24 h during in vitro culture, the rate of O2 consumption increased significantly in a concentration-related and time-dependent manner. Trypanosomes cultured with 100 microM DL-alpha-difluoromethylornithine (DFMO), an irreversible inhibitor of ornithine decarboxylase, were depleted of intracellular putrescine, and the rate of O2 consumption decreased by more than 50%. This effect could be abrogated if 100 microM putrescine was also present. A similar pattern was observed in trypanosomes harvested from rats after 36 h of DFMO treatment. If such trypanosomes were placed in culture for 2 h with 100 microM putrescine, the rate of O2 consumption returned to that of controls. When an intraperitoneal injection of putrescine was given to infected rats 18 h after commencement of DFMO treatment, rates of O2 consumption in the trypanosomes were found to return to control values. The addition of putrescine, spermidine or Mg2+ did not affect rate of O2 consumption in enriched mitochondrial preparations. However, when putrescine was present throughout the preparation of mitochondrial fractions, there was an increase of 23% in O2 uptake, which was 23% higher than in the controls. Putrescine may modulate trypanosomal respiration by stabilizing mitochondrial membranes.
mesh_terms: D000818:Animals; D000518:Eflornithine; D008274:Magnesium / Q000494:pharmacology; D008297:Male; D008928:Mitochondria / Q000378:metabolism; D009952:Ornithine / Q000031:analogs & derivatives / Q000494:pharmacology; D010101:Oxygen Consumption / Q000187:drug effects*; D011700:Putrescine / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D013095:Spermidine / Q000494:pharmacology; D014346:Trypanosoma brucei brucei / Q000187:drug effects / Q000378:metabolism*
chemical_list: D009952:Ornithine; D008274:Magnesium; D013095:Spermidine; D011700:Putrescine; D000518:Eflornithine