The effect of citrate/cis-aconitate on oxidative metabolism during transformation of Trypanosoma brucei.
Monomorphic bloodstream forms of Trypanosoma brucei, grown in the mammal, are deficient in aconitase and 2-oxoglutarate dehydrogenase and they do not respire in the presence of the substrates citrate, cis-aconitate, succinate, proline or 2-oxoglutarate. When grown in vitro low levels of aconitase, succinate oxidase and proline oxidase are detected. Addition of citrate/cis-aconitate at 37 degrees C to bloodstream forms leads to the formation of aconitase and proline oxidase. Most cells undergo an 'abortive' transformation to non-dividing procyclic-like cells while some cells adapt to the presence of the citric acid cycle intermediates and continue to multiply as bloodstream forms. At 27 degrees C and in the presence of citrate/cis-aconitate bloodstream forms transform synchronously to dividing procyclic cells. Within 72 h the rate of respiration with proline, succinate and 2-oxoglutarate becomes similar to that in established procyclic cells while the rate of glucose oxidation decreases. The possible role of citric acid cycle intermediates in determining whether a trypanosome will retain the properties of a bloodstream trypomastigote or differentiate to a procyclic trypomastigote is discussed.
D000156:Aconitic Acid / Q000494:pharmacology*; D000818:Animals; D001831:Body Temperature; D002951:Citrates / Q000494:pharmacology*; D004734:Energy Metabolism / Q000187:drug effects; D005947:Glucose / Q000378:metabolism; D051379:Mice; D010084:Oxidation-Reduction / Q000187:drug effects; D014233:Tricarboxylic Acids / Q000494:pharmacology*; D014346:Trypanosoma brucei brucei / Q000187:drug effects* / Q000254:growth & development / Q000378:metabolism; D014353:Trypanosomiasis, African / Q000469:parasitology; D014370:Tsetse Flies
D002951:Citrates; D014233:Tricarboxylic Acids; D000156:Aconitic Acid; D005947:Glucose