Antioxidants protect the yeast Saccharomyces cerevisiae against hypertonic stress.
Yeast (Saccharomyces cerevisiae) mutants lacking CuZnSOD have been reported to be hypersensitive to hypertonic media and to show increased oxidative damage. This study demonstrates that hypertonic medium (containing 0.8 M NaCl) increases the generation of superoxide and other reactive species in yeast cells. Other sequelae of exposure to hypertonic medium include oxidation of cellular low-molecular weight thiols and decrease in total antioxidant capacity of cellular extracts. deltasod1 mutant is more sensitive than a wild-type strain to colony growth inhibition on a hypertonic medium. Anaerobic conditions, ascorbate, glutathione, cysteine and dithiothreitol are able to ameliorate this growth inhibition but a range of other antioxidants does not protect. The protective ability of the antioxidants does not correlate with the rate of their reactions with superoxide but seems to be conditioned by low redox potential for one-electron oxidation of free radicals of the antioxidants. It suggests that repair of low-redox potential targets rather than prevention of their damage by superoxide is important in the antioxidant protection against oxidative stress induced by hypertonic conditions.
Koziol
Sabina
S
Department of Biochemistry and Cell Biology, University of Rzeszów, Rejtana 16C PL 35-959, Rzeszów, Poland. skoziol@univ.rzeszow.pl
Zagulski
Marek
M
Bilinski
Tomasz
T
Bartosz
Grzegorz
G
D000818:Animals; D000975:Antioxidants / Q000378:metabolism* / Q000494:pharmacology*; D049109:Cell Proliferation / Q000187:drug effects; D005452:Fluoresceins; D009997:Osmotic Pressure; D010084:Oxidation-Reduction / Q000187:drug effects; D018384:Oxidative Stress; D017382:Reactive Oxygen Species / Q000378:metabolism; D012441:Saccharomyces cerevisiae / Q000187:drug effects* / Q000378:metabolism; D012462:Saline Solution, Hypertonic; D013482:Superoxide Dismutase / Q000235:genetics; D013481:Superoxides / Q000378:metabolism
C110400:2',7'-dichlorodihydrofluorescein diacetate; D000975:Antioxidants; D005452:Fluoresceins; D017382:Reactive Oxygen Species; D012462:Saline Solution, Hypertonic; D013481:Superoxides; D013482:Superoxide Dismutase