Modulation of the Mitochondrial Anti-Oxygen Radical Defense of Rat Astroglial Cells in Culture
Oxygen free radicals have been proposed to play a central role in cellular injury that occurs upon postischemic brain tissue reperfusion. Several potential sources of reactive oxygen species (ROS) have been reported: oxidation of accumulated xanthine(X) by xanthine oxidase(XO)1, uncoupling of the electron transport chain with direct transfer to oxygen2, etc... In astroglial cells, two forms of Superoxide dismutase (SOD) namely Cu,Zn- and Mn-SOD localized respectively in the cytosol and in the mitochondria seem to play a fundamental role in ROS scavenging. Therefore we have investigated biochemically and immunochemically various cytosolic and mitochondrial alterations induced by exposure of rat astroglial cells in primary culture to ROS generated by a X/XO mixture added to the growth medium. In all these experimental conditions we examined the level of Cu,Zn-SOD, glutamine synthetase (GS), both cytosol located enzymes, and of Mn-SOD. In parallel to SOD scavenging enzymes analysis, the expression of stress proteins of the 70 kD family was investigated. Moreover, the effect of almitrine — (dialylamino 4′6′-triazinyl-2′)-1-(biS-parafluorobenzydryl)-4 piperazine- vasoactive substance acting on oxygen availability4 on Mn-SOD and heat shock protein expression has been examined.
KeywordsReactive Oxygen Species Glutamine Synthetase Xanthine Oxidase Astroglial Cell Glutamine Synthetase Activity
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- 6.C.N. Oliver, P.E. Starke-Reed, E.R. Stadtman, G.J. Liv, J.M. Carney and R.A. Floyd, Oxidative damage to brain proteins, loss of glutamine synthetase activity and production of free radicals during ischemia reperfusion induced injury to gerbil brain, Prod.Nat.Acad.Sc., USA, 87, 5144 (1990).CrossRefGoogle Scholar
- 7.S. Schull, N.H. Heintz, M. Periasamy, M. Monohar, Y.M. Janssen, J.P. Marsh and B. Moosman, Differential regulation of antioxidant enzymes in response to oxidants J. Biol.Chem. 266,24398 (1991).Google Scholar