Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
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The effect of oxidative stress in vitro induced by iron(2+)plus EDTA and iron(2+)plus EDTA plus H2O2 on synaptosomal and microsomal ion transport systems, as well as on the membrane fluidity was investigated. Oxidative insult reduced Na,K-ATPase activity by 50.7% and Na dependent Ca-uptake measured in choline media by 46.7%.Membrane fluidity was also significantly reduced as observed with the flurescent probe.Incubation of microsomes with radicals generating systems(RGS) led to the loss of ability of membranes to sequester Ca as well as to the decrease of Ca-ATPase activity and to increase of Ca permeability to 125.1%.The relative potency of two RGS to decrease membrane fluidity correlated well with the systems potencies to induce lipid peroxidation.The protection against activity depression by membrane soluble antioxidants(U-74500A,U-83836E, BHT, and stobadine)was dependent on the experimental conditions and on the dose and nature of antioxidant used.Stobadine prevented the decrease in membrane fluidity and Na dependent Ca-uptake, however Na, K-ATPase activity was only partially protected, indicating more complex mechanism of inhibition.Water soluble glutathione had no significant effect on radicals induced inhibition of Ca-ATPase activity. Combination of stobadine and glutathione enhanced stobadine antioxidant efficacy, so drug combination might be beneficial therapeutically.

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Poster Number PAlehotsky,0574
Keywords: oxidative stress, ion transport, rodent brain