González N S, Ceriani C, Algranati I D
Instituto de Investigaciones Bioquímicas Fundación Campomar, Facultad de Ciencias Exactas y Naturales, Universidad de Buenos Aires, Argentina.
Biochem Biophys Res Commun. 1992 Oct 15;188(1):120-8. doi: 10.1016/0006-291x(92)92358-5.
Putrescine uptake in Trypanosoma cruzi epimastigotes is 10 to 50-fold higher than in Leishmania mexicana or Crithidia fasciculata. Polyamine transport in all these trypanosomatids is an energy-dependent process strongly inhibited by the presence of 2,4-dinitrophenol or KCN. Putrescine uptake in T. cruzi and L. mexicana was markedly decreased by the proton ionophore carbonylcyanide m-chlorophenylhydrazone but it was not affected by ouabain, a Na(+)-K+ pump inhibitor. The depletion of intracellular polyamines by treatment of parasite cultures with alpha-difluoromethylornithine elicited a marked induction of putrescine uptake in L. mexicana and C. fasciculata by increasing considerably the Vmax of this process. Conversely, the uptake of putrescine in T. cruzi was essentially unchanged by the same treatment. The differential regulation of putrescine transport in T. cruzi might be related to some distinctive features of polyamine metabolism in this parasite.
克氏锥虫前鞭毛体对腐胺的摄取比墨西哥利什曼原虫或 fasciculata 短膜虫高 10 至 50 倍。在所有这些锥虫中，多胺转运是一个能量依赖过程，2,4 - 二硝基苯酚或 KCN 的存在会强烈抑制该过程。质子离子载体羰基氰化物间氯苯腙可显著降低克氏锥虫和墨西哥利什曼原虫对腐胺的摄取，但它不受钠钾泵抑制剂哇巴因的影响。用α - 二氟甲基鸟氨酸处理寄生虫培养物以耗尽细胞内多胺，通过显著增加该过程的 Vmax，可显著诱导墨西哥利什曼原虫和 fasciculata 短膜虫对腐胺的摄取。相反，相同处理对克氏锥虫中腐胺的摄取基本没有影响。克氏锥虫中腐胺转运的差异调节可能与该寄生虫多胺代谢的一些独特特征有关。
