EFFECTS OF NERVE GROWTH-FACTOR ON BRAIN GLUTATHIONE-RELATED ENZYMES FROM AGED RATS

Neurotrophins, like the nerve growth factor (NGF), trigger a variety o f biological effects in their targets. Stimulating effects on antioxid ant defenses have been postulated to underlie neurotrophic influence o n neuron survival and maintenance. To test whether NGF is capable of i nducing changes in glutathione-related enzymes in the aged cognitively impaired brain, glutathione reductase (GRD), glutathione S-transferas e (GST) and total glutathione peroxidase (GPX) activities were measure d in the striatum, septum, hippocampus and frontal cortex of four Spra gue-Dawley rat groups: young (2 months old), aged (20 months old) untr eated, aged cytochrome c-treated, and aged NGF-treated (icv delivery, 34 mu g during 28 days). All the aged rats utilized in the study were memory impaired according to their performance in the Morris water maz e test. These aged rats showed increases in the activities of septal a nd hippocampal GST, as well as, in the hippocampal, striatal and corti cal GPX. These increases could be interpreted as compensatory response s to cope with the oxidative damage that has been accumulated by the a ged brain. The increases in hippocampal and cortical GPX activity were attenuated by NGF treatment, whereas the neurotrophin induced an incr ease in GRD activity in the striatum of aged rats. These results point out GRD and GPX as possible targets of the neurotrophic effects. (C) Elsevier, Paris.