Giffin B F, McCann P P
Department of Anatomy and Cell Biology, University of Cincinnati College of Medicine, OH 45267-0521.
Acta Trop. 1993 Nov;55(3):181-90. doi: 10.1016/0001-706x(93)90076-n.
A monomorphic strain of Trypanosoma brucei brucei (EATRO 110) was cultured as long slender bloodstream forms in vitro for 24 h with 100 microM Eflornithine HCl. This resulted in depletion of intracellular putrescine, a greater than 50% decrease in spermidine, and a cessation of cell division. These Eflornithine treated trypanosomes were stimulated to synchronously transform to procyclic trypomastigotes by transfer into SDM-79 medium containing the citric acid cycle intermediates citrate and cis-aconitate (CCA). Within 48 h morphological transformation was complete and occurred without any increase in cell numbers. The coadministration of 100 microM putrescine with Eflornithine prevented the depletion of putrescine and abrogated the cytostatic effect of Eflornithine alone, but did not prevent the transformation to procyclic trypomastigotes. Eflornithine-induced short stumpy form trypanosomes resulting from 4 days of culture with 100 microM Eflornithine did not transform to procyclic trypomastigotes in SDM-79 medium unless it contained CCA. We conclude that the high concentration of CCA can trigger transformation in all morphological types of bloodstream form trypanosomes, regardless of their threshold of sensitivity for the stimulus. Furthermore, the CCA-stimulated transformation is not dependent on putrescine and can occur independently of cell division.
将布氏布氏锥虫（EATRO 110）的单形菌株在体外作为长细型血流形式培养24小时，加入100微摩尔盐酸依氟鸟氨酸。这导致细胞内腐胺耗尽，亚精胺减少超过50%，细胞分裂停止。将这些经依氟鸟氨酸处理的锥虫转移至含有柠檬酸循环中间体柠檬酸盐和顺乌头酸盐（CCA）的SDM - 79培养基中，刺激它们同步转化为前循环型锥鞭毛虫。48小时内形态转化完成，且细胞数量没有增加。100微摩尔腐胺与依氟鸟氨酸共同给药可防止腐胺耗尽，并消除依氟鸟氨酸单独的细胞生长抑制作用，但不能阻止向前循环型锥鞭毛虫的转化。用100微摩尔依氟鸟氨酸培养4天产生的依氟鸟氨酸诱导的短粗型锥虫，除非SDM - 79培养基中含有CCA，否则不会在该培养基中转化为前循环型锥鞭毛虫。我们得出结论，高浓度的CCA可触发所有形态类型的血流型锥虫的转化，无论它们对刺激的敏感阈值如何。此外，CCA刺激的转化不依赖于腐胺，且可独立于细胞分裂发生。
