Estrogen Replacement Suppresses Pressor Response and Oxidative Stress Induced by Cage-switch Stress in Ovariectomized Rats

2008 ◽  
Vol 1148 (1) ◽  
pp. 213-218 ◽  
Author(s):  
Keiko Morimoto ◽  
Masami Uji ◽  
Takashi Ueyama ◽  
Hiroko Kimura ◽  
Tomomi Kohno ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Pressor Response ◽  
Ovariectomized Rats ◽  
Estrogen Replacement ◽  
And Oxidative Stress

scholarly journals Comparative effects of estrogen, raloxifene and tamoxifen on endothelial dysfunction, inflammatory markers and oxidative stress in ovariectomized rats

Life Sciences ◽  
2015 ◽  
Vol 124 ◽  
pp. 101-109 ◽  
Author(s):  
Aline Zandonadi Lamas ◽  
Izabela Facco Caliman ◽  
Polyana Lima Meireles Dalpiaz ◽  
Antônio Ferreira de Melo ◽  
Glaucia Rodrigues Abreu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Endothelial Dysfunction ◽  
Inflammatory Markers ◽  
Ovariectomized Rats ◽  
And Oxidative Stress

scholarly journals Effects of estrogen replacement on stress-induced cardiovascular responses via renin-angiotensin system in ovariectomized rats

2016 ◽  
Vol 311 (5) ◽  
pp. R898-R905 ◽  
Author(s):  
Shoko Tazumi ◽  
Naoko Yokota ◽  
Mizuho Kawakami ◽  
Sayo Omoto ◽  
Akira Takamata ◽  
...  
Keyword(s):  
Angiotensin Ii ◽  
Psychological Stress ◽  
Pressor Response ◽  
Renin Angiotensin System ◽  
Cardiovascular Responses ◽  
Ovariectomized Rats ◽  
Separate Experiment ◽  
Estrogen Replacement ◽  
Angiotensin System ◽  
Renin Angiotensin

The purpose of this study was to determine whether chronic estrogen replacement in ovariectomized rats inhibits the pressor response to psychological stress by attenuating the activation of the renin-angiotensin system. Female Wistar rats aged 9 wk were ovariectomized. After 4 wk, the rats were randomly assigned to be implanted subcutaneously with pellets containing either 17β-estradiol (E2) or placebo (Pla). After 4 wk of treatment, the rats underwent cage-switch stress and, in a separate experiment, a subset received an infusion of angiotensin II. The cage-switch stress rapidly elevated blood pressure (BP) and heart rate (HR) as measured by radiotelemetry in both groups. However, the BP and HR responses to the stress were significantly attenuated in the E2 group compared with the Pla group. An angiotensin II type 1 receptor blocker, losartan, given in drinking water, abolished the difference in the pressor response to stress between the two groups. Moreover, the stress-induced elevation in plasma renin activity and angiotensin II concentration was significant in the Pla group, but not in the E2 group. In addition, the expression of renin mRNA in the kidney was lower in the E2 group relative to the Pla group. Finally, we found that intravenous angiotensin II infusion increased BP and decreased HR to a similar degree in both groups. These results suggest that the inhibitory effects of estrogen on psychological stress-induced activation of the renin-angiotensin system could be at least partially responsible for the suppression of the pressor responses to psychological stress seen in estrogen-replaced ovariectomized rats.

scholarly journals Estrogen replacement attenuates stress-induced pressor responses through vasorelaxation via β2-adrenoceptors in peripheral arteries of ovariectomized rats

2018 ◽  
Vol 314 (2) ◽  
pp. H213-H223 ◽  
Author(s):  
Shoko Tazumi ◽  
Sayo Omoto ◽  
Yu Nagatomo ◽  
Mariko Kawahara ◽  
Naoko Yokota-Nakagi ◽  
...  
Keyword(s):  
Mesenteric Artery ◽  
Pressor Response ◽  
Mrna Level ◽  
Treated Group ◽  
Inhibitory Effect ◽  
Ovariectomized Rats ◽  
Peripheral Arteries ◽  
Estrogen Replacement ◽  
Depressor Response ◽  
Pressor Responses

We examined whether chronic estrogen replacement has an inhibitory effect on stress-induced pressor responses via activation of β2-adrenoceptor (AR) in peripheral arteries of ovariectomized rats. Female Wistar rats aged 9 wk were ovariectomized. After 4 wk, pellets containing either 17β-estradiol (E2) or placebo (Pla) were subcutaneously implanted into the rats. After 4 wk of treatment, rats underwent cage-switch stress, and, in a separate experiment, a subset received an infusion of isoproterenol (ISO) with or without pretreatment with the β1-AR blocker atenolol or the β2-AR blocker butoxamine. In addition, the isolated mesenteric artery was used to assess the concentration-related relaxing responses to ISO and the β1- or β2-AR mRNA level. The cage-switch stress-induced pressor response was significantly attenuated in the E2-treated group compared with the Pla-treated group. Pretreatment with atenolol reduced blood pressure responses in both groups. However, butoxamine enhanced the pressor response only in the E2-treated group, resulting in no difference between the two groups. In addition, the intravenous ISO-induced depressor response was significantly enhanced in the E2-treated group compared with the Pla-treated group. Furthermore, the difference in the depressor response was abolished by pretreatment with butoxamine but not by atenolol. In the isolated mesenteric artery, butoxamine caused a rightward shift in ISO-induced concentration-related relaxation in the E2-treated group. The β2-AR mRNA level in the mesenteric artery was higher in the E2-treated group than in the Pla-treated group. These results suggest that estrogen replacement attenuated the stress-induced pressor response probably by suppressing vasoconstriction via activation of β2-ARs in peripheral arteries of ovariectomized rats. NEW & NOTEWORTHY In this study, we show, for the first time, that estrogen replacement has an inhibitory effect on the psychological stress-induced pressor response through vasorelaxation via β2-adrenoceptors, probably due to overexpression of β2-adrenoceptor mRNA, in peripheral arteries of ovariectomized rats.

scholarly journals Modulatory effects of caffeine on oxidative stress and anxiety-like behavior in ovariectomized rats

2016 ◽  
Vol 94 (9) ◽  
pp. 961-972 ◽  
Author(s):  
Ionut Caravan ◽  
Alexandra Sevastre Berghian ◽  
Remus Moldovan ◽  
Nicoleta Decea ◽  
Remus Orasan ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Lipid Peroxidation ◽  
Chronic Administration ◽  
Behavioral Changes ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Plus Maze ◽  
Short Period ◽  
The Brain ◽  
And Oxidative Stress

Menopause is accompanied by enhanced oxidative stress and behavioral changes, effects attenuated by antioxidants. The aim of this study was to evaluate the effects of caffeine on behavior and oxidative stress in an experimental model of menopause. Female rats were divided into the following groups: sham-operated (CON), sham-operated and caffeine-treated (CAF), ovariectomized (OVX), ovariectomized and caffeine-treated (OVX+CAF). Caffeine (6 mg/kg) and vehicle were administered for 21 days (subchronic) and 42 days (chronic), using 2 experimental subsets. Behavioral tests and oxidative stress parameters in the blood, whole brain, and hippocampus were assessed. The subchronic administration of caffeine decreased the lipid peroxidation and improved the antioxidant defense in the blood and brain. The GSH/GGSG ratio in the brain was improved by chronic administration, with reduced activities of antioxidant enzymes and enhanced nitric oxide and malondialdehyde levels. In particular, the lipid peroxidation in the hippocampus decreased in both experiments. The rats became hyperactive after 21 days of treatment, but no effect was observed after chronic administration. In both experimental subsets, caffeine had anxiolytic effects as tested in elevated plus maze. The administration of low doses of caffeine, for a short period of time, may be a new therapeutic approach to modulating the oxidative stress and anxiety in menopause.

The Effects of Yellow Soybean, Black Soybean, and Sword Bean on Lipid Levels and Oxidative Stress in Ovariectomized Rats

2010 ◽  
Vol 80 (2) ◽  
pp. 97-106 ◽  
Author(s):  
Jae Soon Byun ◽  
Young Sun Han ◽  
Sang Sun Lee
Keyword(s):  
Oxidative Stress ◽  
Postmenopausal Women ◽  
Low Density Lipoprotein ◽  
Density Lipoprotein ◽  
Thiobarbituric Acid ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Lipid Levels ◽  
Black Soybean ◽  
And Oxidative Stress

Soy isoflavones have been reported to decrease the risk of atherosclerosis in postmenopausal women. However, the effects of dietary consumption of soybean have not been explored. In this study, we evaluated the effects of consuming yellow soybeans, black soybeans (Glycine max), or sword beans (Canavalia gladiate) on lipid and oxidative stress levels in an ovariectomized rat model. Forty-seven nine-week-old female rats were ovariectomized, randomly divided into four groups, and fed one of the following diets for 10 weeks: a diet supplemented with casein (NC, n = 12), a diet supplemented with yellow soybean (YS, n = 12), a diet supplemented with black soybean (BS, n = 12), or a diet supplemented with sword bean (SB, n = 11). Plasma triglyceride (TG) levels in the BS and SB groups were significantly lower than that in the NC group. Notably, the BS group had significantly lower plasma total cholesterol (TC), and low-density lipoprotein cholesterol (LDL-C) levels than the other groups. Hepatic total lipid levels were significantly lower in the YS and SB groups, and cholesterol levels were significantly lower in the SB group than in the NC group. Superoxide dismutase (SOD) and catalase (CAT) activities were significantly higher in the groups fed beans compared to the NC group. Hepatic thiobarbituric acid reactive substances (TBARS) levels were also significantly lower in the BS and SB groups than the NC group. In conclusion, our results suggest that consumption of various types of beans may inhibit oxidative stress in postmenopausal women by increasing antioxidant activity and improving lipid profiles. Notably, intake of black soybean resulted in the greatest improvement in risk factors associated with cardiovascular disease.

17β-Estradiol prevents oxidative stress and decreases blood pressure in ovariectomized rats

2000 ◽  
Vol 279 (5) ◽  
pp. R1599-R1605 ◽  
Author(s):  
Isabel Hernández ◽  
Juan L. Delgado ◽  
Julian Díaz ◽  
Tomas Quesada ◽  
M. José G. Teruel ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Blood Pressure ◽  
Total Antioxidant Status ◽  
Ovariectomized Rats ◽  
No Production ◽  
Estrogen Replacement ◽  
Lower Plasma ◽  
Vascular Conductance ◽  
Total Antioxidant ◽  
17Β Estradiol

In this study, we tested whether estrogen deficiency is associated with oxidative stress and decreased nitric oxide (NO) production, which could be responsible for an increased blood pressure in ovariectomized rats. Hemodynamic studies were performed on conscious, chronically instrumented rats. Chronic estrogen replacement on ovariectomized rats lowered blood pressure ∼13 mmHg, from 119 ± 3 mmHg in ovariectomized rats to 106 ± 3 mmHg in ovariectomized-treated rats; it was also accompanied by an increase in cardiac index and vascular conductance, achieving hemodynamic values similar to those shown by sham-operated rats. N G-nitro-l-arginine methyl ester administration lowered significantly less the vascular conductance (0.14 ± 0.01 vs. 0.22 ± 0.03 and 0.26 ± 0.01 ml · min−1 · mmHg−1/100 g; P < 0.05) in ovariectomized rats than in the sham-operated and estrogen-treated ovariectomized rats, respectively. Estrogen replacement prevented the lower plasma levels of nitrites/nitrates observed in ovariectomized rats. The lower plasma total antioxidant status and reduced thiol groups and the increase in plasma lipoperoxides presented in ovariectomized animals were reestablished with the estrogen treatment. These results show that estrogen administration decreases blood pressure and increases vascular conductance in ovariectomized rats. This effect may be related to an increase in NO synthesis and/or preventing oxidative stress, then improving endothelial function.

scholarly journals Endothelial Relaxation Mechanisms and Oxidative Stress Are Restored by Atorvastatin Therapy in Ovariectomized Rats

PLoS ONE ◽  
2013 ◽  
Vol 8 (11) ◽  
pp. e80892 ◽  
Author(s):  
Izabela Facco Caliman ◽  
Aline Zandonadi Lamas ◽  
Polyana Lima Meireles Dalpiaz ◽  
Ana Raquel Santos Medeiros ◽  
Glaucia Rodrigues Abreu ◽  
...  
Keyword(s):  
Oxidative Stress ◽  
Ovariectomized Rats ◽  
Atorvastatin Therapy ◽  
And Oxidative Stress
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