title: Redox imbalance influence in the myocardial Akt activation in aged rats treated with DHEA.
abstract: This study examined, in young and old (3 and 24 month-old, respectively) healthy Wistar rats, the in vivo effect of DHEA (10 mg/kg body weight) administered subcutaneously for 5 weeks. Reduced (GSH) and oxidized (GSSG) glutathione levels, glucose-6-phosphate dehydrogenase (G6PDH), glutathione peroxidase (GPx), glutathione-S-transferase (GST) and thioredoxin (Trx) reductase activities, hydrogen peroxide steady-state concentration and Nrf2, GST, Trx-1, Akt and p-Akt expressions were assessed in heart tissue. DHEA treatment significantly increased GST activity in 3 and 24 month-old treated groups. The aging factor diminished hydrogen peroxide concentration and Nrf2 expression, independently of treatment. However, the aging process increased GST, Akt and p-Akt expressions in both 24 month-old groups. The aged group responded differently to DHEA respective to GSSG content, GPx activity and p-Akt concentration. Further studies are needed to form conclusions about the efficacy and safety of DHEA replacement in the elderly, and to better understand DHEA's net effect on oxidative stress parameters and its modulation of signaling cascades.
authors.affiliation: Laboratório de Interação Neuro-Humoral, ICBS, Universidade Federal do Rio Grande do Sul, Brazil. mhvmjacob@hotmail.com
authors.forename: Maria Helena Vianna Metello
authors.initials: MH
authors.lastname: Jacob
authors.forename: Daiane da Rocha
authors.initials: Dda R
authors.lastname: Janner
authors.forename: Alex Sander da Rosa
authors.initials: AS
authors.lastname: Araújo
authors.forename: Matheus Parmegiani
authors.initials: MP
authors.lastname: Jahn
authors.forename: Luiz Carlos Rios
authors.initials: LC
authors.lastname: Kucharski
authors.forename: Tarsila Barros
authors.initials: TB
authors.lastname: Moraes
authors.forename: Carlos Severo
authors.initials: CS
authors.lastname: Dutra Filho
authors.forename: Maria Flavia Marques
authors.initials: MF
authors.lastname: Ribeiro
authors.forename: Adriane
authors.initials: A
authors.lastname: Belló-Klein
mesh_terms: D000375:Aging / Q000378:metabolism*; D000818:Animals; D003687:Dehydroepiandrosterone / Q000494:pharmacology*; D019803:Glutathione Disulfide / Q000378:metabolism; D005979:Glutathione Peroxidase / Q000378:metabolism; D005982:Glutathione Transferase / Q000378:metabolism; D006321:Heart / Q000187:drug effects; D008297:Male; D023421:Models, Animal; D009206:Myocardium / Q000378:metabolism*; D051267:NF-E2-Related Factor 2 / Q000378:metabolism; D010084:Oxidation-Reduction / Q000187:drug effects; D051057:Proto-Oncogene Proteins c-akt / Q000378:metabolism*; D051381:Rats; D017208:Rats, Wistar
chemical_list: D051267:NF-E2-Related Factor 2; D003687:Dehydroepiandrosterone; D005979:Glutathione Peroxidase; D005982:Glutathione Transferase; D051057:Proto-Oncogene Proteins c-akt; D019803:Glutathione Disulfide