Lipid peroxidation, antioxidative enzyme activities, and cytosolic free calcium levels in rat hippocampus-derived cells exposed to free radicals.
To elucidate mechanisms of free radical-induced neuronal cell death, lipid peroxidation measured as thiobarbituric acid-reactive substances (TBARS), three antioxidative enzyme activities (superoxide dismutase, glutathione peroxidase, and catalse), and cytosolic free Ca2+ (Ca2+i) were examined in rat hippocampus-derived cells (HV16-4) exposed to free radicals generated by a hypoxanthine-xanthine oxidase system. The viability of cells decreased with an increase in numbers of free radical positive cells in a dose-dependent manner of xanthine oxidase. The protein-bound TBARS did not change, whereas free TBARS increased at 135% of initial value. No remarkable change was observed in three antioxidative enzyme activities. On the other hand, Ca2+i increased after exposure followed by cell death. Furthermore, the addition of Co2+, a nonspecific Ca2+ channel blocker, delayed the increase of Ca2+i and subsequent cell death. These findings suggested that the influx of Ca2+ played a crucial role for HV16-4 cell death induced by free radicals.
Tamura
S
S
Department of Veterinary Clinical Pathobiology, Graduate School of Agricultural and Life Sciences, The University of Tokyo, Japan.
Takanohashi
A
A
Bonkobara
M
M
Matsuki
N
N
Onodera
T
T
Ono
K
K
D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002374:Catalase / Q000378:metabolism*; D016923:Cell Death / Q000187:drug effects / Q000502:physiology*; D002460:Cell Line; D002462:Cell Membrane / Q000187:drug effects / Q000648:ultrastructure; D002470:Cell Survival / Q000187:drug effects; D002478:Cells, Cultured; D003600:Cytosol / Q000187:drug effects / Q000378:metabolism; D005609:Free Radicals / Q000494:pharmacology; D005979:Glutathione Peroxidase / Q000378:metabolism*; D006624:Hippocampus / Q000166:cytology* / Q000378:metabolism; D019271:Hypoxanthine / Q000494:pharmacology; D007700:Kinetics; D015227:Lipid Peroxidation / Q000187:drug effects*; D008933:Mitochondrial Swelling / Q000187:drug effects; D009474:Neurons / Q000166:cytology / Q000187:drug effects / Q000378:metabolism*; D015388:Organelles / Q000187:drug effects / Q000648:ultrastructure; D051381:Rats; D013482:Superoxide Dismutase / Q000378:metabolism*; D014969:Xanthine Oxidase / Q000494:pharmacology
D005609:Free Radicals; D019271:Hypoxanthine; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase; D014969:Xanthine Oxidase; D002118:Calcium