title: Oxidative damage and antioxidant defense in thymus of malnourished lactating rats.
abstract: OBJECTIVE
  Malnutrition has been associated with oxidative damage by altered antioxidant protection mechanisms. Specifically, the aim of this study was to evaluate oxidative damage (DNA and lipid) and antioxidant status (superoxide dismutase [SOD], glutathione peroxidase [GPx], and catalase [CAT] mRNA, and protein expression) in thymus from malnourished rat pups.
  
  
  METHODS
  Malnutrition was induced during the lactation period by the food competition method. Oxidative DNA damage was determined quantifying 8-oxo-7, 8-dihydro-2'-deoxyguanosine adduct by high-performance liquid chromatography. Lipid peroxidation was assessed by the formation of thiobarbituric acid-reactive substances. Levels of gene and protein expression of SOD, GPx, and CAT were evaluated by real-time polymerase chain reaction and Western blot, respectively. Antioxidant enzyme activities were measured spectrophotometrically.
  
  
  RESULTS
  Oxidative DNA damage and lipid peroxidation significantly increased in second-degree (MN-2) and third-degree malnourished (MN-3) rats compared with well-nourished rats. Higher amounts of oxidative damage, lower mRNA expression, and lower relative concentrations of protein, as well as decreased antioxidant activity of SOD, GPx, and CAT were associated with the MN-2 and MN-3 groups.
  
  
  CONCLUSIONS
  The results of this study demonstrated that higher body-weight deficits were related to alterations in antioxidant protection, which contribute to increased levels of damage in the thymus. To our knowledge, this study demonstrated for the first time that early in life, malnutrition leads to increased DNA and lipid oxidative damage, attributable to damaged antioxidant mechanisms including transcriptional and enzymatic activity alterations. These findings may contribute to the elucidation of the causes of previously reported thymus dysfunction, and might explain partially why children and adults who have overcome child undernourishment experience immunologic deficiencies.
authors.affiliation: Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, México City, Mexico; Posgrado en Biología Experimental, Universidad Autónoma Metropolitana-Iztapalapa, México City, Mexico.
authors.forename: Graciela
authors.initials: G
authors.lastname: Gavia-García
authors.affiliation: Centro de Nanociencias y Micro y Nanotecnologías, Instituto Politécnico Nacional, Unidad Profesional Adolfo López Mateos, México City, Mexico.
authors.forename: Haydeé
authors.initials: H
authors.lastname: González-Martínez
authors.affiliation: Sección de Estudios de Posgrado, Escuela Superior de Medicina, Instituto Politécnico Nacional, México City, Mexico.
authors.forename: Ángel
authors.initials: Á
authors.lastname: Miliar-García
authors.affiliation: Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, México City, Mexico.
authors.forename: Edmundo
authors.initials: E
authors.lastname: Bonilla-González
authors.affiliation: Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, México City, Mexico.
authors.forename: María de Los Ángeles
authors.initials: Mde L
authors.lastname: Rosas-Trejo
authors.affiliation: Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, México City, Mexico.
authors.forename: Mina
authors.initials: M
authors.lastname: Königsberg
authors.affiliation: Departamento de Atención a la Salud, Universidad Autónoma Metropolitana-Xochimilco, México City, Mexico.
authors.forename: Oralia
authors.initials: O
authors.lastname: Nájera-Medina
authors.affiliation: Departamento de Investigación Básica, Instituto Nacional de Geriatría, México City, Mexico.
authors.forename: Armando
authors.initials: A
authors.lastname: Luna-López
authors.affiliation: Departamento de Ciencias de la Salud, Universidad Autónoma Metropolitana-Iztapalapa, México City, Mexico. Electronic address: mcgt@xanum.uam.mx.
authors.forename: María Cristina
authors.initials: MC
authors.lastname: González-Torres
mesh_terms: D000818:Animals; D000975:Antioxidants / Q000378:metabolism*; D001835:Body Weight; D002374:Catalase / Q000378:metabolism; D004249:DNA Damage; D005260:Female; D005979:Glutathione Peroxidase / Q000378:metabolism; D007774:Lactation; D015227:Lipid Peroxidation; D044342:Malnutrition / Q000378:metabolism*; D009752:Nutritional Status; D010084:Oxidation-Reduction; D018384:Oxidative Stress; D010088:Oxidoreductases / Q000378:metabolism*; D012333:RNA, Messenger / Q000378:metabolism; D017208:Rats, Wistar; D013482:Superoxide Dismutase / Q000378:metabolism; D017392:Thiobarbituric Acid Reactive Substances / Q000378:metabolism; D013950:Thymus Gland / Q000378:metabolism*
chemical_list: D000975:Antioxidants; D012333:RNA, Messenger; D017392:Thiobarbituric Acid Reactive Substances; D010088:Oxidoreductases; D002374:Catalase; D005979:Glutathione Peroxidase; D013482:Superoxide Dismutase
keywords: Antioxidants; CAT; DNA damage; GPx; Lipid peroxidation; Malnutrition; Oxidative stress; SOD