title: Brain biomolecules oxidation in portacaval-shunted rats.
abstract: BACKGROUND
  Oxidative stress induced by a high ammonia concentration has been suggested to be implicated in the pathophysiology of hepatic encephalopathy (HE). Therefore, oxidative damage of brain biomolecules could contribute towards explaining the neurological and motor alterations observed in HE.
  
  
  METHODS
  Portacaval-shunted (PCS) rats (n = 5) were used as an animal model of chronic HE. Plasma and brain ammonia were measured by the l-glutamate dehydrogenase method. Reactive oxygen species was measured by the dichlorodihydrofluorescein diacetate method. Lipid peroxidation was measured as thiobarbituric acid-reactive substances (TBARS) by a colorimetric method; malondialdehyde (MDA) and 4-hydroxy-2-noneal (HNE) were measured by HPLC and an immunological method respectively. Protein oxidation (carbonylation) was measured as total carbonyl after labelling with 2,4-dinitrophenyl hydrazine (DNPH) using a spectrophotometric method. Individual protein oxidation was studied, after labelling with DNPH and its separation by one-dimensional (1D) electrophoresis, by an immunological method.
  
  
  RESULTS
  Ammonia-induced oxidative stress in PCS rats was associated with increased MDA and HNE, together with increased protein oxidation, evidenced by total carbonyl quantification and by the analysis of individual protein bands separated by 1D electrophoresis. However, lipid peroxidation measured as TBARS did not show differences.
  
  
  CONCLUSIONS
  Our data show an increased evidence of oxidative stress in PCS rat brain; moreover, PCS rat brain proteins are oxidized (carbonylated), some proteins being more sensitive to oxidation than others. These data also show that at least six specific brain proteins in PCS rats are highly sensitive to carbonylation. Identification of these proteins may be crucial for a better understanding of HE pathophysiology.
authors: Departamento de Bioquímica y Biología Molecular, Facultad de Farmacia, Universidad de Sevilla, Sevilla, Spain.
authors: Pilar
authors: P
authors: Carbonero-Aguilar
authors: Maria Del Mar
authors: Mdel M
authors: Diaz-Herrero
authors: Olga
authors: O
authors: Cremades
authors: Manuel
authors: M
authors: Romero-Gómez
authors: Juan
authors: J
authors: Bautista
mesh_terms: D000447:Aldehydes / Q000378:metabolism; D000641:Ammonia / Q000097:blood*; D000818:Animals; D001921:Brain / Q000378:metabolism*; D002851:Chromatography, High Pressure Liquid; D004586:Electrophoresis; D005969:Glutamate Dehydrogenase; D006501:Hepatic Encephalopathy / Q000209:etiology / Q000503:physiopathology*; D015227:Lipid Peroxidation / Q000502:physiology; D008297:Male; D008315:Malondialdehyde / Q000378:metabolism; D010084:Oxidation-Reduction; D018384:Oxidative Stress / Q000502:physiology*; D011167:Portacaval Shunt, Surgical; D051381:Rats; D017208:Rats, Wistar; D017382:Reactive Oxygen Species / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances
chemical_list: D000447:Aldehydes; D017382:Reactive Oxygen Species; D017392:Thiobarbituric Acid Reactive Substances; D008315:Malondialdehyde; D000641:Ammonia; D005969:Glutamate Dehydrogenase; C027576:4-hydroxy-2-nonenal