Role for iron in reactive oxygen species-mediated cytotoxicity to cultured rat gastric mucosal cells

1991 ◽  
Vol 260 (4) ◽  
pp. G556-G563 ◽  
Author(s):  
H. Hiraishi ◽  
A. Terano ◽  
S. Ota ◽  
H. Mutoh ◽  
M. Razandi ◽  
...  

The gastric epithelium is exposed to oxygen species that are generated within the lumen. Reactive oxygen species, enzymatically generated, cause injury to cultured rat gastric mucosal cells. Much interest has been focused on the role of iron in producing oxidant-mediated injury to the gastric mucosa, because iron is a catalyst that promotes the production of .OH possibly from O2-. and H2O2 (Haber-Weiss reaction) or from H2O2 alone (Fenton reaction). With the use of an iron chelator and an iron binding protein, we examined the role of iron in producing oxidant-mediated injury to cultured gastric mucosal cells. Reactive oxygen species and H2O2 were generated by hypoxanthine-xanthine oxidase and glucose-glucose oxidase, respectively, in buffer without iron. Pretreatment with deferoxamine diminished hypoxanthine-xanthine oxidase-induced 51Cr release from prelabeled cells, dose dependently. Furthermore, addition of deferoxamine to the reactive oxygen species-generating system also protected against the injury. However, apotransferrin (which binds extracellular iron) failed to protect cells. Pretreatment with .OH scavengers was partially protective. Depletion of glutathione with diethyl maleate enhanced reactive oxygen species-mediated cytolysis; such cytolysis was inhibited by deferoxamine. Deferoxamine also decreased 51Cr release induced by glucose-glucose oxidase. We conclude that intracellular iron plays a crucial role in mediating oxygen radical damage to gastric mucosal cells. The .OH, produced from H2O2 by the iron-catalyzed Fenton reaction, seems to be the main mediator of oxidant-induced cytotoxicity to gastric mucosal cells in vitro.

Nanoscale ◽  
2018 ◽  
Vol 10 (25) ◽  
pp. 11820-11830 ◽  
Author(s):  
Marco Pelin ◽  
Laura Fusco ◽  
Cristina Martín ◽  
Silvio Sosa ◽  
Javier Frontiñán-Rubio ◽  
...  

Graphene based nanomaterials induce a reactive oxygen species-mediated mitochondrial depolarization, caused by the activation of NADH dehydrogenase and xanthine oxidase.


1989 ◽  
Vol 66 (3) ◽  
pp. 1321-1327 ◽  
Author(s):  
D. S. Lee ◽  
E. A. McCallum ◽  
D. M. Olson

A differentiation-arrested primary cell culture model was used to examine the role of reactive oxygen species in the control of prostacyclin (PGI2) production in the perinatal rat lung. Coincubation of the lung cells with arachidonic acid (AA) and xanthine (X, 0.25 mM) plus xanthine oxidase (XO, 10 mU/ml) or with AA and glucose (25 mM) plus glucose oxidase (25 mU/ml) augmented the AA-induced PGI2 output. Superoxide dismutase (10 U/ml) did not alter the X + XO effect, whereas catalase (10 U/ml) eliminated both X + XO and glucose plus glucose oxidase effects. H2O2 (1–200 microM) showed a dose-related biphasic augmentation with peak stimulation at 20 microM. Catalase again blocked this effect, but dimethylthiourea, a hydroxyl radical scavenger, did not. A 20-min pretreatment of the cells with X + XO, glucose plus glucose oxidase, or H2O2, however, diminished the capacity of the cells to convert exogenous AA to PGI2. This pretreatment effect was also blocked by catalase. The responses were similar in lung cells obtained from day 20 rat fetuses (term = 22 days) and 1-day-old newborn rats. Lactate dehydrogenase release was not detected during treatment periods but increased significantly after exposure to reactive oxygen species.(ABSTRACT TRUNCATED AT 250 WORDS)


2006 ◽  
Vol 96 (S1) ◽  
pp. S31-S33 ◽  
Author(s):  
Mari-Carmen Gomez-Cabrera ◽  
Agustín Martínez ◽  
Gustavo Santangelo ◽  
Federico V. Pallardó ◽  
Juan Sastre ◽  
...  

We have recently reported that xanthine oxidase is involved in the generation of free radicals in exhaustive exercise. Allopurinol, an inhibitor of xanthine oxidase, prevents it. The aim of the present work was to elucidate the role of exercise-derived reactive oxygen species in the cell signalling pathways involved in the adaptation to exercise in man. We have found that exercise causes an increase in the activity of plasma xanthine oxidase and an activation of NF-κB in peripheral blood lymphocytes after marathon running. This activation is dependent on free radical formation in exercise: treatment with allopurinol completely prevents it. In animal models, we previously showed that NF-κB activation induced by exhaustive physical exercise leads to an increase in the expression of superoxide dismutase, an enzyme involved in antioxidant defence. We report evidence in man that reactive oxygen species act as signals in exercise as decreasing their formation prevents activation of important signalling pathways which can cause useful adaptations in cells.


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