title: Chromium (VI) can activate and impair antioxidant defense system.
abstract: The changes in glutathione-dependent cycle enzymes and catalase activities under Cr(VI)-induced oxidative stress were investigated in two distinct cell lines: L-41-human epithelial-like cells and HLF-fetal human diploid lung fibroblasts, which differ in tissue origin, proliferation, and antioxidant enzymes activities. The chromium concentrations from 1 to 5 μM cause nontoxic effects and activate antioxidant enzymes to overcome oxidative stress. In spite of some differences in the endogenous antioxidant activities, both cell lines reveal the same range of toxic concentrations (20-30 μM). The irreversible inhibition of glutathione-dependent antioxidant enzymes develops under toxic concentrations and serves as a marker of toxicity. The endogenous antioxidant activity influences time-dependent expression of Cr(VI) toxicity and the dynamics of antioxidant enzymes activity under nontoxic conditions. The cell antioxidant defense system is an important marker of the cell adaptive capacity under nontoxic and toxic conditions.
authors.affiliation: Department of Physics of Biological Systems, Andronikashvili Institute of Physics, 6, Tamarashvili St, 0177 Tbilisi, Georgia.
authors.forename: Nino
authors.initials: N
authors.lastname: Asatiani
authors.forename: Tamar
authors.initials: T
authors.lastname: Kartvelishvili
authors.forename: Marina
authors.initials: M
authors.lastname: Abuladze
authors.forename: Lali
authors.initials: L
authors.lastname: Asanishvili
authors.forename: Nelly
authors.initials: N
authors.lastname: Sapojnikova
mesh_terms: D000975:Antioxidants / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism; D002460:Cell Line; D002857:Chromium / Q000633:toxicity*; D004789:Enzyme Activation / Q000187:drug effects; D005979:Glutathione Peroxidase / Q000378:metabolism; D005980:Glutathione Reductase / Q000378:metabolism; D006801:Humans; D018384:Oxidative Stress / Q000187:drug effects
chemical_list: D000975:Antioxidants; D002857:Chromium; D002374:Catalase; D005979:Glutathione Peroxidase; D005980:Glutathione Reductase