Abstract: The changes in the neuroactive amino acid contents, GABA metabolism and TCA reactions have been studied in rat brain regions under experimental morphine withdrawal (MW). MW was developed by means of the cessation of morphine intraperitoneal injections 1 and 36 hours, 3 and 7 days after the course of morphine administration for 7 days. In cortex the significant increase in the contents of glutamate, glutamine, asparagine, and alanine was observed in remote terms of MW. In cerebellum MW led to the decrease in the levels of glutamine and asparagine and increase in glycine level, followed by the GABA-transaminase activation and the succinate dehydrogenase inhibition. In thalamus prolongation of MW caused to the further inhibition of the activities of the GABA-catabolising enzymes. The changes observed in the amino acids levels and the GABA shunt activity are likely to be explained by indirect adaptation of the brain regions differing in the opioid receptors contents to protracted morphine administration.
Reference: Vinitskaya A.G., Lelevich S.V., Lelevich V.V., Kozlovsky A.V., Doroshenko Ye.M., GABA metabolism and neuroactive amino acids in rat brain under morphine withdrawal syndrome, Biomeditsinskaya khimiya, 2007, vol: