LESION OF THE NIGROSTRIATAL NEURONS BY 6-HYDROXYDOPAMINE INDUCES CHANGES IN RAT-BRAIN GLUTATHIONE-S-TRANSFERASE

Wistar rats were lesioned into the nigrostriatal pathway with 6-OHDA. The D-amphetamine-induced circling behavior test was performed to eval uate lesion efficiency. Animals that showed more than 620 turns/90 min were named totally lesioned animals (TLA). The group of rats that per formed less than 620 turns/90 min was named partially lesioned animals (PLA). The contents of DA and its catabolites in the striata of these groups, and in the same tissue of the untreated animals, were measure d. Moreover, the striatal glutathione-S-transferase (GST) specific act ivity for all groups was tested, and the kinetics parameters for GST p urified from the whole brain were evaluated from other three similar g roups. The striatal DA depletion in TLA was greater than in PLA. Stria tal GST activity showed a significant bilateral increase in PLA, where as TLA exhibited only an ipsilateral augment. There were also differen ces between groups about the kinetic parameters of the purified brain enzyme. The possible role of GST on the interindividual lesion respons e difference was analyzed.