Glutamine Synthetase Activity and Glutamate Uptake in Hippocampus and Frontal Cortex in Portal Hypertensive Rats

Overview

Journal World J Gastroenterol

Publisher Baishideng Publishing Group

Specialty Gastroenterology

Date 2009 Jun 18

PMID 19533812

Citations 3

Authors

Gabriela Beatriz Acosta

Maria Alejandra Fernandez

Diego Martin Rosello

Maria Lujan Tomaro

Karina Balestrasse

Abraham Lemberg

Affiliations

Soon will be listed here.

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.

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