Effect of normobaric hyperoxia on antioxidant defenses of hela and CHO cells

Johan J.P. Gille, Heleen M. Wortelboer, Hans Joenje*

*Corresponding author for this work

Research output: Contribution to journalArticleAcademicpeer-review


The effect of increased intracellular oxygen activation on cellular antioxidant defenses in CHO and HeLa cells was studied. In both cell types, hyperoxic exposure (up to 4 days, 600-700 mm Hg O2) and in CHO cells menadione (up to 3 days, 15 μM) failed to affect the enzymatic antioxidant defenses Mn-containing superoxide dismutase (Mn-SOD), CuZn-SOD, catalase and glutathione peroxidase. The markedly increased antioxidant enzyme activities observed in a recently obtained oxygen-tolerant CHO variant persisted under normoxia. These data suggest that the synthesis of antioxidant enzymes is constitutive. Glutathione levels of HeLa cells did not respond to hyperoxia whereas in CHO cells hyperoxia and menadione exposure resulted in a 2- and 7-fold increase in glutathione contents, respectively. However, considering the large variations in glutathione contents observed under normal culture conditions, it is uncertain whether this increase is to be considered as a true adaptive response.

Original languageEnglish
Pages (from-to)85-91
Number of pages7
JournalFree Radical Biology and Medicine
Issue number2
Publication statusPublished - 1988

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