Spermidine is essential for normal proliferation of trypanosomatid protozoa.
Trypanosomatid parasites containing a metabolically unstable ornithine decarboxylase (ODC) are naturally resistant to high levels of alpha-difluoromethylornithine (DFMO) because this ODC inhibitor, though causing a drastic reduction of intracellular putrescine, elicits only a moderate decrease of the spermidine endogenous pool. In this study we have used a combination of DFMO with cyclohexylamine (CHA; bis-cyclohexylammonium sulfate), an inhibitor of spermidine synthase, to reach a more complete depletion of spermidine. Under these conditions we have observed the arrest of proliferation not only in trypanosomatids with stable ODC but also in parasites with an enzyme of high turnover rate. In all cases the reinitiation of proliferation occurred only after the addition of exogenous spermidine, and neither putrescine nor spermine were able to induce the same effect.
González
N S
NS
Instituto de Investigaciones Bioquímicas Fundación Campomar, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires and CONICET, A. Machado 151, 1405, Buenos Aires, Argentina.
Huber
A
A
Algranati
I D
ID
D000818:Animals; D016831:Crithidia fasciculata / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism; D003514:Cyclohexylamines / Q000494:pharmacology; D000518:Eflornithine / Q000494:pharmacology; D004791:Enzyme Inhibitors / Q000494:pharmacology; D009955:Ornithine Decarboxylase / Q000378:metabolism; D011700:Putrescine / Q000378:metabolism / Q000494:pharmacology; D013095:Spermidine / Q000378:metabolism* / Q000494:pharmacology; D011436:Spermidine Synthase / Q000037:antagonists & inhibitors / Q000378:metabolism; D013096:Spermine / Q000378:metabolism / Q000494:pharmacology; D014349:Trypanosoma cruzi / Q000187:drug effects / Q000201:enzymology / Q000254:growth & development* / Q000378:metabolism
D003514:Cyclohexylamines; D004791:Enzyme Inhibitors; D013096:Spermine; D011436:Spermidine Synthase; D009955:Ornithine Decarboxylase; D013095:Spermidine; D011700:Putrescine; D000518:Eflornithine