Campos Cristina, Casali Karina Rabello, Baraldi Dhãniel, Conzatti Adriana, Araújo Alex Sander da Rosa, Khaper Neelam, Llesuy Susana, Rigatto Katya, Belló-Klein Adriane
Universidade Federal do Rio Grande do Sul, Sarmento Leite, 500 Bairro Farroupilha, 90050-170 Porto Alegre, RS, Brazil.
Instituto de Cardiologia do Rio Grande do Sul, 90620-001 Porto Alegre, RS, Brazil.
Oxid Med Cell Longev. 2014;2014:218749. doi: 10.1155/2014/218749. Epub 2014 Mar 10.
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.
本研究测试了低剂量（比17-β雌二醇药理剂量低40%）是否与药理剂量一样有效，能改善心血管参数并降低心脏氧化应激。将雌性Wistar大鼠（每组n = 9只）分为三组：（1）去卵巢组（Ovx），（2）用低剂量（LE；0.2毫克）治疗21天的去卵巢动物组，以及（3）皮下注射高剂量（HE；0.5毫克）17-β雌二醇组。进行了血流动力学评估和用于评估自主神经系统调节的频谱分析。测量了心肌超氧化物歧化酶（SOD）和过氧化氢酶（CAT）活性、氧化还原比（GSH/GSSG）、总自由基捕获抗氧化能力（TRAP）、过氧化氢和超氧阴离子浓度。HE组和LE组的血流动力学功能和心率变异性均有改善。这些变化与TRAP、GSH/GSSG、SOD和CAT的增加有关。与Ovx组相比，在接受雌激素治疗的组中还观察到过氧化氢和超氧阴离子减少。我们的结果表明，低剂量雌激素在促进心血管功能和降低氧化应激方面与高剂量一样有效，从而支持在临床环境中使用低剂量雌激素以尽量减少与雌激素治疗相关风险的方法。
