The effect of methioninesulfoximine, an inhibitor of glutamine synthetase, on the levels of amino acids in the intact and decorticated rat neostriatum.

The glutamate terminals in rat rostral neostriatum were removed on one side by ipsilateral frontal cortical ablation. Intraperitoneal administration of L-methioninesulfoximine (MSO), an inhibitor of glutamine synthetase, induced different changes in amino acid concentration in the rostral neostriatum on the intact and decorticated sides. Glutamine was more reduced on the decorticated side than on the intact side. Glutamate changed less, but decreased more on the intact than on the lesioned side. There seems to be a correlation between the decrease in glutamine and the increase in alanine on both sides. GABA and taurine did not change significantly. The results indicate that the formation of glutamine probably formed from released glutamate is lower on the decorticated side than on the intact side.