Efficacy of a Low Dose of Estrogen on Antioxidant Defenses and Heart Rate Variability

Authors
Campos, Cristina; Rabello Casali, Karina; Baraldi, Dhãniel; Conzatti, Adriana; Rosa Araújo, Alex Sander da; Khaper, Neelam; Llesuy, Susana Francisca; Rigatto, Katya; Belló Klein, Adriane
Publication Year
2014
Language
English
Format
article
Status
Published version
Description
This study tested whether a low dose (40% less than the pharmacological dose of 17-β estradiol) would be as effective as the pharmacological dose to improve cardiovascular parameters and decrease cardiac oxidative stress. Female Wistar rats (n = 9/group) were divided in three groups: (1) ovariectomized (Ovx), (2) ovariectomized animals treated for 21 days with low dose (LE; 0.2 mg), and (3) high dose (HE; 0.5 mg) 17-β estradiol subcutaneously. Hemodynamic assessment and spectral analysis for evaluation of autonomic nervous system regulation were performed. Myocardial superoxide dismutase (SOD) and catalase (CAT) activities, redox ratio (GSH/GSSG), total radical-trapping antioxidant potential (TRAP), hydrogen peroxide, and superoxide anion concentrations were measured. HE and LE groups exhibited an improvement in hemodynamic function and heart rate variability. These changes were associated with an increase in the TRAP, GSH/GSSG, SOD, and CAT. A decrease in hydrogen peroxide and superoxide anion was also observed in the treated estrogen groups as compared to the Ovx group. Our results indicate that a low dose of estrogen is just as effective as a high dose into promoting cardiovascular function and reducing oxidative stress, thereby supporting the approach of using low dose of estrogen in clinical settings to minimize the risks associated with estrogen therapy.
Fil: Campos, Cristina. Universidade Federal do Rio Grande do Sul; Brasil
Fil: Rabello Casali, Karina. Instituto de Cardiologia do Rio Grande do Sul; Brasil
Fil: Baraldi, Dhãniel. Universidade Federal do Rio Grande do Sul; Brasil
Fil: Conzatti, Adriana. Universidade Federal do Rio Grande do Sul; Brasil
Fil: Rosa Araújo, Alex Sander da. Universidade Federal do Rio Grande do Sul; Brasil
Fil: Khaper, Neelam. Lakehead University; Canadá
Fil: Llesuy, Susana Francisca. Universidad de Buenos Aires; Argentina. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Instituto de Bioquímica y Medicina Molecular. Universidad de Buenos Aires. Facultad de Farmacia y Bioquímica. Instituto de Bioquímica y Medicina Molecular; Argentina
Fil: Rigatto, Katya. Universidade Federal de Ciências da Saúde de Porto Alegre; Brasil
Fil: Belló Klein, Adriane. Universidade Federal do Rio Grande do Sul; Brasil
Subject
Estrogen
Antioxidant defenses
Heart rate variability
Otras Ciencias Biológicas
Ciencias Biológicas
CIENCIAS NATURALES Y EXACTAS
Access level
Open access
License
https://creativecommons.org/licenses/by/2.5/ar/
Repository
CONICET Digital (CONICET)
Institution
Consejo Nacional de Investigaciones Científicas y Técnicas
OAI Identifier
oai:ri.conicet.gov.ar:11336/30296