Metabolic responses in discrete regions of rat brain following acute administration of glutamate

• Published in: Neurochemical research 2003-09, Vol.28 (9), p.1345-1349
• Main Authors: BAWARI, Meenakshi, NAGESH BABU, G
• Format: Article
• Language: English
• Subjects: Alanine Transaminase - metabolism; Animals; Aspartate Aminotransferases - metabolism; Biological and medical sciences; Brain - drug effects; Brain - enzymology; Brain - metabolism; Cerebral Cortex - drug effects; Cerebral Cortex - enzymology; Corpus Striatum - drug effects; Corpus Striatum - enzymology; Dizocilpine Maleate - pharmacology; Excitatory Amino Acid Antagonists - pharmacology; Fundamental and applied biological sciences. Psychology; Glutamate Dehydrogenase - metabolism; Glutamic Acid - administration & dosage; Glutamic Acid - metabolism; Glutamic Acid - pharmacology; Hippocampus - drug effects; Hippocampus - enzymology; L-Lactate Dehydrogenase - metabolism; Male; Organ Specificity; Rats; Rats, Wistar; Vertebrates: nervous system and sense organs
• ISSN: 0364-3190; 1573-6903
• DOI: 10.1023/A:1024940230816

Glutamate is a major excitatory neurotransmitter in the mammalian brain. Nevertheless, high extracellular levels of this amino acid have been shown to be toxic to several neuronal populations, but no data are available to show how glutamate homeostasis is altered in response to local infusion of glutamate. In the present study, 1 microM of glutamate was stereotactically injected into cerebral cortex, striatum, and hippocampus of adult rat brain, and the activities of key metabolic enzymes, lactate dehydrogenase, glutamate dehydrogenase, aspartate aminotransferase, and alanine aminotransferase were evaluated by postmortem analysis in tissue homogenates. The results show that glutamate bolus, induced significant alterations in vivo glutamate and energy metabolism, as evidenced by marked alterations in these enzyme activities, whereas dizocilpine, a glutamate receptor antagonist, negated many of the effects induced by high glutamate. However, the degree of involvement of these observations in glutamate-induced neurotoxicity remains to be ascertained.