MOLECULAR MECHANISMS OF CELLULAR INJURY PRODUCED BY NEUROTOXIC AMINO-ACIDS THAT GENERATE REACTIVE OXYGEN SPECIES

There is now strong experimental evidence that the basic precursors fo r the synthesis of catechol(amine) and indolamine neurotransmitters, t yrosine and tryptophan can act as generators of ROS (reactive oxygen s pecies): peroxides, superoxide and peroxyradicals. The consequences of free radicals formation from precursors during oxidative degradation process, their possible participation in electron transfer/addition re actions and chain processes involving cell antioxidant defense system were presented and discussed. Although the generation of neurotoxic RO S by tyrosine and tryptophan is accepted to occur in the presented mod el systems, doubts can exist as to the situation in vivo, which may be completely different and remain to be explored. The relevance of the present findings with regard to a variety of neurological diseases can not be ignored.