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Resumo(s)
In the present work, the mode of cell death
induced by Pb in Saccharomyces cerevisiae was studied.
Yeast cells Pb-exposed, up to 6 h, loss progressively the
capacity to proliferate and maintained the membrane
integrity evaluated by the fluorescent probes bis(1,3-
dibutylbarbituric acid trimethine oxonol) and propidium
iodide. Pb-induced death is an active process, requiring the
participation of cellular metabolism, since the simultaneous
addition of cycloheximide attenuated the loss of cell
proliferation capacity. Cells exposed to Pb accumulated
intracelullarly reactive oxygen species (ROS), evaluated by
2′,7′-dichlorodihydrofluorescein diacetate. The addition of
ascorbic acid (a ROS scavenger) strongly reduced the
oxidative stress and impaired the loss of proliferation
capacity in Pb-treated cells. Pb-exposed cells displayed
nuclear morphological alterations, like chromatin fragmentation,
as revealed by diaminophenylindole staining. Together,
the data obtained indicate that yeast cells exposition
to 1 mmol/l Pb results in severe oxidative stress which can
be the trigger of programmed cell death by apoptosis.
Descrição
Palavras-chave
Apoptosis Ascorbic acid Lead Heavy metals toxicity Oxidative stress ROS production
Contexto Educativo
Citação
Editora
Springer Verlag