SPERMINE PARTIALLY NORMALIZES IN-VIVO ANTIOXIDANT DEFENSE POTENTIAL IN CERTAIN BRAIN-REGIONS IN TRANSIENTLY HYPOPERFUSED RAT-BRAIN

Activities of the antioxidant enzymes such as superoxide dismutase (Cu ,Zn-SOD), glutathione peroxidase (GSH-Px), glutathione reductase (GSSG -R) as well as the level of reduced glutathione and the concentration of thiobarbituric acid-reactive substance (TEARS) in brain regions in transiently hypoperfused rat brain with or without intravenous infusio n of spermine were evaluated. Cerebral hypoperfusion was induced by te mporary occlusion of common carotid arteries for 30 min and subsequent ly, by reperfusion for 60 min. Infusion of spermine reversed the decre ase in SOD activity in the cerebral cortex, striatum, hippocampus, hyp othalamus and midbrain, and amounted to 50.1 U, 61.5 U, 50.3 U, 30.0 U , 38.0 U, respectively, while GSH-Px restored to normal values only in the cerebral cortex and striatum and amounted to 100 U and 110 U, res pectively. During hypoperfusion/reperfusion and after use of spermine no changes in GSSG-R were seen in the hypothalamus and midbrain. The a ctivity of GSSG-R was in accordance with the control for the striatum and amounted to 39.0 IU after using spermine. GSH content returned to normal values in the striatum and midbrain after i.v. use of spermine and amounted to 210 and 240 nmol/g of wet tissue, respectively. In add ition, the production of TEARS dropped markedly (P < 0.05) in the hipp ocampus and midbrain and amounted to 100 and 105 mu mol/g of wet tissu e, respectively. Partially beneficial effect of spermine could result from the inhibition of free radical generation and capability of chela te formation with iron ions.