KAINIC ACID-INDUCED LIPID-PEROXIDATION - PROTECTION WITH BUTYLATED HYDROXYTOLUENE AND U78517F IN PRIMARY CULTURES OF CEREBELLAR GRANULE CELLS

The generation of free radicals in the progression of kainic acid (KA) -mediated neuronal death has been implicated in both in vitro and in v ivo studies. In the present study, the association between KA-induced neurodegeneration and the appearance of lipid peroxidation products wa s investigated and compared to three well characterized free radical g enerating (FRG) systems: 200 muM ferrous ammonium sulfate (FAS), 20 mu M copper (Cu2+), and 0.01 U/ml xanthine oxidase/2.3 mM purine/2.4 muM transferrin (XO). KA caused a dose-dependent increase in conjugated di ene and lipid hydroperoxide formation as did the FRG systems. The anti oxidant, butylated hydroxytoluene (BHT), decreased both FRG system- an d KA-induced lipid peroxidation by approximately 60-70%. Unlike BHT, t he potency of the lipid peroxidation inhibitor, U78517F, depended upon the system utilized to induce free radical generation. U78517F was mo st potent in attenuating FAS-induced lipid peroxidation (100 nM), foll owed by KA (1.5 muM), and then Cu2+ and XO (> 2 muM). Results were con firmed by measurement of cytolysis through the release of lactic dehyd rogenase (LDH). These data provide further evidence that the generatio n of free radicals, subsequently leading to membrane disruption, is ce ntral to the mechanism of KA-elicited neuronal death in cultures of ce rebellar granule cells.