Toxicity of Two Pairs of Epimeric lonophorous Antibiotics Towards Tetrahymena pyriformis. Structure-Activity Relationship
TL;DR: Results showed different durations of cell division inhibition which increased in the following order: epigrisorixin Tetrahymena, between nigericin/grisorxin and between each antibiotic and its epimer, may be due respectively to structural differences at carbons 30 and 28.
About: This article is published in Archiv für Protistenkunde.The article was published on 1994-08-01. It has received 3 citations till now. The article focuses on the topics: Tetrahymena pyriformis & Nigericin.
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TL;DR: A study of the toxicity of epinigericin towards the ciliate Tetrahymena pyriformis showed that this molecule stopped cell division, increased cell volume and led to a more basic intracellular pH.
Abstract: A study of the toxicity of epinigericin, an antibiotic ionophor, towards the ciliate Tetrahymena pyriformis showed that this molecule stopped cell division, increased cell volume and led to a more basic intracellular pH. The action of epinigericin was probably linked to its function as an ionophor. The ionic selectivity of this molecule is still not known. The raising of the intracellular pH of ciliates by this antibiotic may be linked to its toxic action and its ion-transport mechanism in Tetrahymena. *** DIRECT SUPPORT *** AG903066 00009
7 citations
Cites background from "Toxicity of Two Pairs of Epimeric l..."
...In the exponential growth phase, this antibiotic caused a marked decrease of DNA and RNA synthesis (Bamdad et al. 1994)....
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TL;DR: Chlorpropham (CIPC), widely used in agriculture as a herbicide, displays genotoxic and antimitotic properties and toxicity is lasting, still disturbing cells even after several generations.
3 citations
TL;DR: Cell fractionation of Tetrahymena demonstrates that the cytosolic compartment is implicated in this bioconversion of nigericin, and non-impairment after adding actinomycin D and cycloheximide to the ciliate culture suggests that the induction mechanism involves no mRNA synthesis, nor any de novo synthesis of protein.
Abstract: Nigericin, an ionophorous antibiotic, is converted to epinigericin by the ciliateTetrahymena pyriformis. Bioconversion occurs in the presence of intact cells but not with broken cells (sonicated ciliates). However, broken cells obtained from intact ciliates pretreated with 1 mg/l of nigericin, before sonication, converted nigericin to epinigericin. Non-impairment after adding actinomycin D and cycloheximide to the ciliate culture suggests that the induction mechanism involves no mRNA synthesis, nor any de novo synthesis of protein. Cell fractionation ofTetrahymena demonstrates that the cytosolic compartment is implicated in this bioconversion.
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307 citations
TL;DR: Using a potentiometric method, both the stoechiometry and the stability of complexes formed in methanol between the three natural ionophores and cations IA and IIA have been obtained.
Abstract: Using a potentiometric method, both the stoechiometry and the stability of complexes formed in methanol between the three natural ionophores and cations IA and IIA have been obtained. With alkali m...
44 citations
TL;DR: The effect of DMSO on Tetrahymena was dependent not only on the concentration of the compound but also on the physiological state of the cells, and nuclear division was inhibited and that cell division resulted in one anucleate and one nucleate daughter cell.
Abstract: Increasing concentrations of dimethyl sulphoxide (DMSO) affect vacuole formation in Tetrahymena , as measured quantitatively by the uptake of carmine particles. The rate of vacuole formation decreased to about 50% of the control value in 5.0% DMSO (v/v) and to zero in 7.5%. At the latter concentration, the inhibition was expressed immediately; however, the effect of 1-h exposure was reversible after removal of DMSO by washing. In vivo observations revealed abnormal function of the contractile vacuole in 7.5% DMSO, while cell motility and cell division appeared to be unaffected. Although cell division occurred there was little or no increase in cell number, as studied over a cell generation time. Feulgen preparations showed that nuclear division was inhibited and that cell division resulted in one anucleate and one nucleate daughter cell. This effect was also observed in some dividing cells at lower concentrations of DMSO. The effect of DMSO on Tetrahymena was dependent not only on the concentration of the compound but also on the physiological state of the cells.
40 citations
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25 citations