Acosta GB, Fernández MA, Roselló DM, Tomaro ML, Balestrasse K, Lemberg A. Glutamine synthetase activity and glutamate uptake in hippocampus and frontal cortex in portal hypertensive rats. World J Gastroenterol 2009; 15(23): 2893-2899 [PMID: 19533812 DOI: 10.3748/wjg.15.2893]
Corresponding Author of This Article
Dr. Gabriela Beatriz Acosta, Institute of Pharmacological Research (ININFA), National Research Council of Argentina (CONICET) and University of Buenos Aires, Junín 956. 5th floor, C1113AAD, Buenos Aires, Argentina. gacosta@ffyb.uba.ar
Article-Type of This Article
Brief Articles
Open-Access Policy of This Article
This article is an open-access article which was selected by an in-house editor and fully peer-reviewed by external reviewers. It is distributed in accordance with the Creative Commons Attribution Non Commercial (CC BY-NC 4.0) license, which permits others to distribute, remix, adapt, build upon this work non-commercially, and license their derivative works on different terms, provided the original work is properly cited and the use is non-commercial. See: http://creativecommons.org/licenses/by-nc/4.0/
World J Gastroenterol. Jun 21, 2009; 15(23): 2893-2899 Published online Jun 21, 2009. doi: 10.3748/wjg.15.2893
Glutamine synthetase activity and glutamate uptake in hippocampus and frontal cortex in portal hypertensive rats
Gabriela Beatriz Acosta, María Alejandra Fernández, Diego Martín Roselló, María Luján Tomaro, Karina Balestrasse, Abraham Lemberg
Gabriela Beatriz Acosta, Institute of Pharmacological Research (ININFA), National Research Council of Argentina (CONICET) and University of Buenos Aires, Junín 956. 5th floor, C1113AAD, Buenos Aires, Argentina
María Alejandra Fernández, Diego Martín Roselló, Abraham Lemberg, Laboratory of Portal Hypertension, School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 956. 5th floor, C1113AAD, Buenos Aires, Argentina
María Luján Tomaro, Karina Balestrasse, Department of Biological Chemistry, School of Pharmacy and Biochemistry, University of Buenos Aires, Junín 596. 5th floor, C1113AAD, Buenos Aires, Argentina
Author contributions: Acosta GB, Fernández MA, and Roselló DM contributed equally to this work; Acosta GB performed glutamate uptake, contributed new reagents and analyed data; Tomaro ML and Balestrasse K performed glutamine synthetase; Acosta GB and Lemberg A designed research and wrote the paper.
Correspondence to: Dr. Gabriela Beatriz Acosta, Institute of Pharmacological Research (ININFA), National Research Council of Argentina (CONICET) and University of Buenos Aires, Junín 956. 5th floor, C1113AAD, Buenos Aires, Argentina. gacosta@ffyb.uba.ar
Telephone: +54-11-49615949/6784
Fax: +54-11-49638593
Received: January 21, 2009 Revised: April 24, 2009 Accepted: May 1, 2009 Published online: June 21, 2009
Abstract
AIM: To study glutamine synthetase (GS) activity and glutamate uptake in the hippocampus and frontal cortex (FC) from rats with prehepatic portal vein hypertension.
METHODS: Male Wistar rats were divided into sham-operated group and a portal hypertension (PH) group with a regulated stricture of the portal vein. Animals were sacrificed by decapitation 14 d after portal vein stricture. GS activity was determined in the hippocampus and FC. Specific uptake of radiolabeled L-glutamate was studied using synaptosome-enriched fractions that were freshly prepared from both brain areas.
RESULTS: We observed that the activity of GS increased in the hippocampus of PH rats, as compared to control animals, and decreased in the FC. A significant decrease in glutamate uptake was found in both brain areas, and was more marked in the hippocampus. The decrease in glutamate uptake might have been caused by a deficient transport function, significantly and persistent increase in this excitatory neurotransmitter activity.
CONCLUSION: The presence of moderate ammonia blood levels may add to the toxicity of excitotoxic glutamate in the brain, which causes alterations in brain function. Portal vein stricture that causes portal hypertension modifies the normal function in some brain regions.
