MELATONIN REDUCES KAINATE-INDUCED LIPID-PEROXIDATION IN HOMOGENATES OF DIFFERENT BRAIN-REGIONS

Melatonin protection against in vitro kainic acid-induced oxidative da mage in homogenates from different rat brain regions is shown. Brain-d isrupted cell homogenates from cerebral cortex, cerebellum, hippocampu s, hypothalamus, and corpus striatum were incubated with kainate (11.7 mM) with or without different concentrations of melatonin (0.1-4 mM). The concentration of malonaldehyde and 4-hydroxyalkenals was measured as an index of Lipid peroxidation. Wistar and Sprague-Dawley rats wer e used. When administered with kainate, melatonin markedly reduced lip id peroxidation in every brain region of both rat strains. The reducti on in lipid peroxidation by melatonin Tvas concentration-dependent and varied from 10% to 100%. The protection conferred by melatonin is lik ely due, at least in part, to its newly discovered, free radical scave nging ability.