Effects of lipid peroxidation on neurotransmitters uptake by rat synaptosomes

This paper described the effect of in vitro peroxidation achieved by 60 s or 5 min exposure to 60 microM Fe2+ with 200 microM ascorbic acid, on selected properties of rat brain synaptosomes reflecting some steps of chemical neurotransmission. The studies have revealed dramatic differences between dopamine, GABA and choline high affinity uptake systems in response to peroxidation. The uptake of calcium by synaptosomes submitted to free radical oxidation, mostly its K+-depolarization-dependent portion, was significantly suppressed. In contrast, peroxidation appeared not to influence the transmembrane synaptosomal potential. It is concluded, that peroxidation of synaptic endings modifies the lipid content of synaptoplasmatic membranes and consequently leads to severe disturbances in the function of neurotransmitter uptake systems and depolarization-dependent calcium channels.