Hepatic encephalopathy, ammonia, glutamate, glutamine and oxidative stress
Journal Title: Annals of Hepatology - Year 2009, Vol 8, Issue 2
Abstract
This review addresses recent and not so recent works that emphasize on the mechanisms by which liver damage can induce encephalopathy. Hepatic encephalopathy constitutes an intriguing complication in severe liver acute and chronic disease, whose pathophysiology is still not completely understood. In this pathology, alterations in normal brain function are associated with morphological and functional impairments of astrocytes and neurons. A wide spectrum of psychoneurological symptoms has been described and the anatomical substratum is usually associated with brain edema and intracranial hypertension, as well as with changes in the function of brain cells. An increase in blood ammonia, toxic to the brain, depends on the activity of the enzyme glutamine synthetase, the glutamine/glutamate cycle and the brain capacity to eliminate toxic substances. When the concentration of the excitotoxic neurotransmitter glutamate is increased, it acts as a toxic agent, especially when its specific transporters are altered and its uptake is decreased. Glutamine has also been recently considered a toxic substance when its concentration is high, and consequently contributes to brain edema. Finally, the formation of reactive oxygen species, basically produced by mitochondria, influence with their toxic action on membrane lipids, proteins and DNA. In conclusion we suggest that at least these four elements are involved directly in the mechanism of hepatic encephalopathy.
Authors and Affiliations
Abraham Lemberg, Maria Fernández
Keywords
Related Articles
- EP ID EP77849
- DOI -
- Views 123
- Downloads 0
Probiotics in non-alcoholic fatty liver disease: which and when
Non-alcoholic fatty liver disease (NAFLD) is a common and serious disease. Literature reports the central role of the gut-liver axis in the pathogenesis of NAFLD, and recently suggests that the microbiota is a casual fac...
Does the size of the needle influence the number of portal tracts obtained through percutaneous liver biopsy?
Aim. Liver biopsy (LB) is often essential for the diagnosis and staging of chronic viral hepatitis. The aim of our paper was to establish if the size of the biopsy needle influences the number of portal tracts obtained...
Good outcomes of liver transplantation for hepatitis C at a low volume centre
Background and aims. Concerns exist about outcomes of liver transplantation (LT) from low volume centres, especially for hepatitis C (HCV) patients. The aim of the study was to assess patient outcomes as well as their pr...
Hepatic encephalopathy, ammonia, glutamate, glutamine and oxidative stress
This review addresses recent and not so recent works that emphasize on the mechanisms by which liver damage can induce encephalopathy. Hepatic encephalopathy constitutes an intriguing complication in severe liver acute a...
Acute Liver Failure
Acute liver failure is a rare but often catastrophic illness affecting the liver and multiple organ systems. Patients with acute liver failure require a multidisciplinary approach for adequate management. With improved...