title: Oxidative stress in mouse liver caused by dietary amino acid deprivation: protective effect of methionine.
abstract: The aim of this work was to evaluate the effects of a diet depleted of amino acids (protein-free diet, or PFD), as well as the supplementation with methionine (PFD+Met), on the antioxidant status of the female mouse liver. With this purpose, cytosolic protein spots from two-dimensional non-equilibrium pH gel electrophoresis were identified by several procedures, such as mass spectrometry, Western blot, gel matching and enzymatic activity. PFD decreased the contents of catalase (CAT), peroxiredoxin I (Prx-I), and glutathione peroxidase (GPx) by 67%, 37% and 45%, respectively. Gene expression analyses showed that PFD caused a decrease in CAT (-20%) and GPx (-30%) mRNA levels but did not change that of Prx-I. It was also found that, when compared to a normal diet, PFD increased the liver contents of both reactive oxygen species (+50%) and oxidized protein (+88%) and decreased that of glutathione (-45%). Supplementation of PFD with Met prevented these latter effects to varying degrees, whereas CAT, Prx-I and GPx mRNA levels resulted unmodified. Present results suggest that dietary amino acid deprivation deranges the liver antioxidant defences, and this can be, in part, overcome by supplementation with Met.
authors.affiliation: Instituto de Investigaciones Biológicas, Facultad de Ciencias Exactas y Naturales, Universidad Nacional de Mar del Plata-CONICET, CC 1245, 7600, Mar del Plata, Argentina.
authors.forename: Virginia P
authors.initials: VP
authors.lastname: Ronchi
authors.forename: Ana M
authors.initials: AM
authors.lastname: Giudici
authors.forename: Julieta R
authors.initials: JR
authors.lastname: Mendieta
authors.forename: Veronica J
authors.initials: VJ
authors.lastname: Caballero
authors.forename: Andrea N
authors.initials: AN
authors.lastname: Chisari
authors.forename: Pedro M
authors.initials: PM
authors.lastname: Sanllorenti
authors.forename: Rubén D
authors.initials: RD
authors.lastname: Conde
mesh_terms: D000818:Animals; D002374:Catalase / Q000378:metabolism; D003600:Cytosol / Q000378:metabolism; D018753:Diet, Protein-Restricted / Q000009:adverse effects*; D005260:Female; D005978:Glutathione / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D008099:Liver / Q000378:metabolism; D008715:Methionine / Q000494:pharmacology*; D051379:Mice; D018384:Oxidative Stress / Q000187:drug effects*; D050050:Protein Carbonylation; D012333:RNA, Messenger / Q000378:metabolism; D017382:Reactive Oxygen Species / Q000378:metabolism
chemical_list: D012333:RNA, Messenger; D017382:Reactive Oxygen Species; D008715:Methionine; D002374:Catalase; D005979:Glutathione Peroxidase; D005978:Glutathione