scholarly journals Involvement of Brainstem Catecholaminergic Inputs to the Hypothalamic Paraventricular Nucleus in Estrogen Receptor α Expression in this Nucleus during Different Stress Conditions in Female Rats

Endocrinology ◽  
2004 ◽  
Vol 145 (11) ◽  
pp. 4917-4926 ◽  
Author(s):  
Maria Amelita C. Estacio ◽  
Hiroko Tsukamura ◽  
Beverly A. S. Reyes ◽  
Yoshihisa Uenoyama ◽  
Helen I’Anson ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Paraventricular Nucleus ◽  
Estrogen Receptor Α ◽  
Stress Conditions ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Cell Group ◽  
Slight Reduction ◽  
Significant Difference ◽  
Cell Groups

Abstract In the present study, we determined the involvement of brainstem catecholaminergic inputs to the paraventricular nucleus (PVN) on estrogen receptor α (ERα) expression in this nucleus during conditions of 48-h fasting, 2-deoxy-d-glucose (2DG)-induced acute glucoprivation and 1-h immobilization, in ovariectomized rats. Our approach was to examine the effect of lesioning catecholaminergic inputs to the PVN using DSAP [saporin-conjugated anti-DBH (dopamine-β-hydroxylase)]. Bilateral injection of DSAP into the PVN, 2 wk before stress, prevented fasting-, glucoprivation-, and immobilization-induced increase in ERα-immunopositive cells in the PVN. The DBH-immunoreactive (ir) terminals in the PVN were severely depleted by DSAP injection in all experimental groups. Among the brainstem noradreneregic cell groups examined, DBH-ir cell bodies were significantly reduced in the A2 region of all experimental groups treated with DSAP compared with the saporin- and vehicle-injected controls. PVN DSAP injection caused a small, but not significant, decrease in A1 DBH-ir cell bodies in fasted and immobilized rats, and a significant, but slight, reduction in A1 DBH-ir cell bodies of iv 2DG- injected rats compared with PVN vehicle-injected or PVN saporin-injected controls. The A6 DBH-ir cell bodies in all experimental groups treated with DSAP, saporin, or vehicle did not show any significant difference. These results suggest that the brainstem catecholaminergic inputs to the PVN, especially from the A2 cell group, may play a major role in mediating the induction of ERα expression in the PVN by metabolic stressors such as fasting, acute glucoprivation, and less specific stressors, such as immobilization, in female rats.

scholarly journals Temporal expression of estrogen receptor α in the hypothalamus and medulla oblongata during fasting: a role of noradrenergic neurons

2006 ◽  
Vol 190 (3) ◽  
pp. 593-600 ◽  
Author(s):  
Beverly A S Reyes ◽  
Hiroko Tsukamura ◽  
Helen I’Anson ◽  
Maria Amelita C Estacio ◽  
Kanjun Hirunagi ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Estrogen Receptor Α ◽  
Brain Regions ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Noradrenergic Neurons ◽  
Anatomical Relationship ◽  
Relationship Of ◽  
Lh Secretion

Fasting-induced LH suppression is augmented by estrogen in female rats. We investigated the temporal changes in the number of estrogen receptor α (ERα)-immunoreactive (ir) cells in various brain regions in ovariectomized rats fasted for 6, 24, 30, and 48 h, commencing at 1300 h. We also determined the anatomical relationship of ERα immunoreactivity and dopamine-β-hydroxylase (DBH) neurons in the A2 region of the nucleus of the solitary tract (NTS) and the paraventricular nucleus (PVN). The number of ERα-ir cells significantly increased after 30 h from the onset of fasting in the PVN and NTS compared with the unfasted controls and was sustained until 48 h. In the A2 region of 48-h fasted rats, 46.75% DBH-ir cells expressed ERα, and this was significantly higher than in unfasted controls (8.16% DBH-ir cells expressed ERα). In the PVN, most ERα-ir neurons were juxtaposed with DBH-ir varicosities. These results suggest that ERα is expressed in specific brain regions at a defined time from the onset of fasting. In addition, the anatomical relationship of noradrenergic and ERα-ir neurons in the A2 region and PVN may suggest a role for estrogen in increasing the activity of noradrenergic neurons in the A2 region and enhancing sensitivity of the PVN to noradrenergic input arising from the lower brainstem and thereby augmenting the suppression of LH secretion during fasting.

scholarly journals Evidence for Ligand-Independent Activation of Hippocampal Estrogen Receptor-α by IGF-1 in Hippocampus of Ovariectomized Rats

Endocrinology ◽  
2016 ◽  
Vol 157 (8) ◽  
pp. 3149-3156 ◽  
Author(s):  
Elin M. Grissom ◽  
Jill M. Daniel
Keyword(s):  
Estrogen Receptor ◽  
Steroid Receptor ◽  
Estrogen Receptor Α ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Independent Manner ◽  
Steroid Receptor Coactivator ◽  
Intracerebroventricular Infusion

In the absence of ovarian estrogens, increased levels of estrogen receptor (ER)α in the hippocampus are associated with improvements in cognition. In vitro evidence indicates that under conditions of low estrogen, growth factors, including Insulin-Like Growth Factor 1 (IGF-1), can activate ERα and regulate ERα-mediated transcription through mechanisms that likely involve modification of phosphorylation sites on the receptor. The goal of the current work was to investigate a role for IGF-1 in ligand-independent activation of ERα in the hippocampus of female rats. Ovariectomized rats received a single intracerebroventricular infusion of IGF-1 and hippocampi were collected 1 or 24 hours later. After 1 h, IGF-1 increased hippocampal levels of phosphorylated ERα at serine 118 (S118) as revealed by Western blotting. Coimmunoprecipitation revealed that at 1 hour after infusion, IGF-1 increased association between ERα and steroid receptor coactivator 1, a histone acetyltransferase that increases transcriptional activity of phosphorylated ERα. IGF-1 infusion increased levels of the ERα-regulated proteins ERα, choline acetyltransferase, and brain-derived neurotrophic factor in the hippocampus 24 hours after infusion. Results indicate that IGF-1 activates ERα in ligand-independent manner in the hippocampus via phosphorylation at S118 resulting in increased association of ERα with steroid receptor coactivator 1 and elevation of ER-regulated proteins. To our knowledge, these data are the first in vivo evidence of ligand-independent actions of ERα and provide a mechanism by which ERα can impact memory in the absence of ovarian estrogens.

Selected Contribution: Estrogen receptor-α antisense decreases brain estrogen receptor levels and affects ventilation in male and female rats

2001 ◽  
Vol 91 (4) ◽  
pp. 1886-1892 ◽  
Author(s):  
Shashita R. Inamdar ◽  
Kathleen M. Eyster ◽  
Evelyn H. Schlenker
Keyword(s):  
Estrogen Receptor ◽  
Aspartic Acid ◽  
Estrogen Receptor Α ◽  
Neonatal Rat ◽  
Female Rats ◽  
Antisense Oligodeoxynucleotide ◽  
Protein Levels ◽  
Ventilatory Responses ◽  
Rat Pups ◽  
Male And Female Rats

We hypothesized that administration of an antisense oligodeoxynucleotide (ODN) to estrogen receptor (ER)-α mRNA decreases the ER protein in the neonatal rat brain, alters the sex-specific ventilatory responses to aspartic acid in rats, and counteracts the effects of testosterone proportionate (TP) in females. One-day-old rat pups were injected intraventricularly with vehicle, antisense ER ODN, or scrambled ODN control. Additional groups of females received TP or vehicle and one of the three treatments. Brain ER protein levels were decreased by 65% at 6 h and 35% at 24 h after antisense ODN. Aspartic acid decreased ventilation in all groups of weanling males and females except ER ODN-treated females and TP-vehicle-treated females. Aspartic acid decreased ventilation in all groups of adult females except those given TP and in males. Weanling ER ODN-treated rats were shorter and weighed less than controls. Only adult ER ODN-treated males exhibited these traits. Thus neonatal ER affects aspartic acid modulation of breathing and body growth in a sex-specific and developmental manner.

scholarly journals Estradiol Stimulates Apolipoprotein A-IV Gene Expression in the Nucleus of the Solitary Tract Through Estrogen Receptor-α

Endocrinology ◽  
2014 ◽  
Vol 155 (10) ◽  
pp. 3882-3890 ◽  
Author(s):  
Ling Shen ◽  
Yin Liu ◽  
David Q.H. Wang ◽  
Patrick Tso ◽  
Stephen C. Woods ◽  
...  
Keyword(s):  
Gene Expression ◽  
Estrogen Receptor ◽  
Nucleus Tractus Solitarius ◽  
Body Weight Gain ◽  
Gene Promoter ◽  
Estrogen Receptor Α ◽  
Inhibitory Effect ◽  
Female Rats ◽  
Upstream Region ◽  
Apolipoprotein A

Abstract Although estrogens have been implicated in the regulation of apolipoprotein A-IV (apo A-IV) gene expression in the nucleus tractus solitarius, previous studies have not defined the molecular mechanism. The aim of this study was to examine the transcriptional mechanisms involved in regulation of apo A-IV gene expression. Using cultured primary neuronal cells from rat embryonic brainstems, we found that treatment with 10nM 17β-estradiol-3-benzoate (E2) or 4,4′,4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol (an estrogen receptor [ER]α agonist), but not 2,3-bis(4-hydroxyphenyl)-propionitrile (an ERβ agonist), significantly increased apo A-IV gene expression, compared with vehicle treatment. This effect of E2 was abolished when the cells were incubated with E2 linked to BSA, which prevents E2 from entering cells, implying that a nongenomic mechanism of E2 is not involved. Two putative estrogen response elements were identified at the 5′-upstream region of the apo A-IV gene promoter, but only 1 of them was able to recruit ERα, leading to increased apo A-IV gene expression, as determined by chromatin immunoprecipitation assay and luciferase activity analysis. A cyclic regimen of E2 or 4,4′,4″-(4-propyl-[1H]-pyrazole-1,3,5-triyl) trisphenol treatment for 8 cycles (4 d/cycle, mimicking the ovarian cycle of female rats) in ovariectomized female rats significantly reduced food intake and body weight gain and increased apo A-IV gene expression in the nucleus tractus solitarius, relative to vehicle. These data collectively demonstrate that nuclear ERα is the primary mediator of E2's action on apo A-IV gene expression and suggest that increased signaling of endogenous apo A-IV may at least partially mediate E2-induced inhibitory effect on feeding.

Estrogenic influence on the regulation of hepatic estrogen receptor-α and serum level of angiotensinogen in female rats

2001 ◽  
Vol 78 (1) ◽  
pp. 83-88 ◽  
Author(s):  
Anneli Stavréus-Evers ◽  
Paolo Parini ◽  
Bo Freyschuss ◽  
Walter Elger ◽  
Gudrun Reddersen ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Serum Level ◽  
Estrogen Receptor Α ◽  
Female Rats

scholarly journals Rapid Estrogen Receptor-α Activation Improves Ischemic Tolerance in Aged Female Rats through a Novel Protein Kinase Cε-Dependent Mechanism

Endocrinology ◽  
2009 ◽  
Vol 150 (2) ◽  
pp. 889-896 ◽  
Author(s):  
Jennifer L. Novotny ◽  
Amy M. Simpson ◽  
Nanette J. Tomicek ◽  
Timothy S. Lancaster ◽  
Donna H. Korzick
Keyword(s):  
Estrogen Receptor ◽  
Protein Kinase ◽  
Estrogen Receptor Α ◽  
Ischemic Tolerance ◽  
Female Rats ◽  
Dependent Mechanism ◽  
Novel Protein

scholarly journals The Effect of Tomato Juice in Increasing Ki-67 Expression and Epithelial Thickness on The Vaginal Wall of Menopausal Rats

2019 ◽  
Vol 11 (2) ◽  
pp. 152-8
Author(s):  
Juminten Saimin ◽  
Hendy Hendarto ◽  
Soetjipto Soetjipto
Keyword(s):  
Cell Proliferation ◽  
Vaginal Wall ◽  
Tomato Juice ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Distilled Water ◽  
Ki 67 ◽  
Treatment Groups ◽  
Epithelial Thickness ◽  
Significant Difference

BACKGROUND: Dyspareunia and pain due to the decrease of vaginal wall thickness usually happen in menopausal women. The reduction of estrogen levels cause the decreasing of cell proliferation and the thinning of vaginal wall epithelium. Tomato (Solanum lycopersicum) is a source of phytoestrogens, which produce estrogenic effects. This study aims to assess the effect of tomato juice on Ki-67 expression and epithelial thickness of the vaginal wall in menopausal rats.METHODS: This was an experimental study using Sprague-Dawley rats. Twenty-four female rats, aged 4 months and weighing 150-200 grams, were divided into 4 groups. Each group consisted of 6 rats. Negative control (NC) group was group of rats with sham procedure and performed by distilled water for 28 days. Positive control (PC) group was group of bilateral ovariectomized rats and performed by distilled water for 28 days. The first treatment (T1) group was group of bilateral ovariectomized rats, given tomato juice at dose of 11g/200g body weight (BW)/day. The second treatment (T2) group was group of bilateral ovariectomized rats, given tomato juice at dose of 15g/200g BW/day. Data analysis was done with Anova, multiple comparisons and regression test.RESULTS: The group with lowest Ki-67 expression was PC group (2.52±0.60). The expression of Ki-67 in treatment groups (T1 and T2) was higher than PC group, but lower than NC group. There was no significant difference between groups (p=0.771). The lowest epithelial thickness was found in PC group (21.19±3.96) and the highest was found in the treatment groups (38.73±12.43). There was positive correlation between tomato juice and epithelial thickness (p=0.647).CONCLUSION: Tomato juice increases Ki-67 expression and epithelial thickness on the vaginal wall of menopausal rats. The increase of epithelial thickness follows the administration dose, but Ki-67 expression does not exceed in the control rats. Tomato juice increases the cell proliferation of vaginal wall on menopausal rats, however the increase is still within normal limits.KEYWORDS: epithelial thickness, Ki-67, menopause, tomato juice

scholarly journals The Combination of High Calcium Milk with Citrus maxima Peels Ethanolic Extract Increased Bone Density of Ovariectomized Rats

2017 ◽  
Vol 6 (2) ◽  
pp. 42
Author(s):  
Ragil S. Dianingati ◽  
Annisa Novarina ◽  
Amanita K. Hana ◽  
Laeli Muntafi'ah ◽  
Endang Lukitaningsih
Keyword(s):  
Estrogen Receptor ◽  
Bone Density ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Menopausal Woman ◽  
Good Prospect ◽  
Sprague Dawley ◽  
Docking Score ◽  
High Calcium ◽  
Citrus Maxima

Osteoporosis is a common problem in menopause woman. The main cause is lack of estrogen hormone. Commonly, prevention therapy is by consuming high calcium milk, but it is not effective. Bali orange’s peel (Citrus maxima Merr.) is a waste material but known contains phytoestrogen according to previous study. Considering of this result, fortification of high calcium milk and Bali orange’s peel is expected to be an effective solution for osteoporosis in menopause woman. This research began with extraction of Bali orange’s peel (BPE) using ethanol 70% by maceration method. Ovariectomized Sprague Dawley female rats as the model of post menopausal woman were treated by BPE for 28 days. The doses of BPE was given to rats is 500 and 1000 mg/KgBW combined with high calcium milk. Bone density was determined using digital microradiography, the profile showed the increase of bone density in group that treated with combination of BPE 1000 mg/Kg BW and high calcium milk compare to control and given only milk groups. Docking molecular showed that BPE’s active compound which are hesperidin and naringin have interaction with estrogen receptor α and β. Docking score of naringin with ER α and β are -19,97; -18,99 respectively. Meanwhile the docking score of hesperidin with ER α and β are -19,98; +49,92 respectively. Overall, the result of this research showed that fortification of BPE with high calcium milk has good prospect to develop as effective therapy of osteoporosis.Keywords : Citrus maxima Merr., phytoestrogen, osteoporosis, high calcium milk, estrogen receptor 

Effects of estrogen on thermoregulatory tail vasomotion and heat-escape behavior in freely moving female rats

2001 ◽  
Vol 280 (5) ◽  
pp. R1341-R1347 ◽  
Author(s):  
Takayoshi Hosono ◽  
Xiao-Ming Chen ◽  
Aya Miyatsuji ◽  
Tamae Yoda ◽  
Kyoko Yoshida ◽  
...  
Keyword(s):  
Heat Dissipation ◽  
Escape Behavior ◽  
Female Rats ◽  
Ovariectomized Rats ◽  
Thermoregulatory Behavior ◽  
Ambient Temperatures ◽  
Significant Difference ◽  
Vasomotor Activity ◽  
Freely Moving ◽  
Escape Behaviors

Effects of estrogen on thermoregulatory vasomotion and heat-escape behavior were investigated in ovariectomized female rats supplemented with estrogen (replaced estrogen rats) or control saline (low estrogen rats). First, we measured tail temperature of freely moving rats at ambient temperatures (Ta) between 13 and 31°C. Tail temperature of the low estrogen rats was higher than that of the replaced estrogen rats at Ta between 19 and 25°C, indicating that the low estrogen rats exhibit more skin vasodilation than the replaced estrogen rats. There was no significant difference in oxygen consumption and core temperature between the two groups. Second, we analyzed heat-escape behaviors in a hot chamber where rats could obtain cold air by moving in and out of a reward area. The low estrogen rats kept Ta at a lower level than did the replaced estrogen rats. These results imply that the lack of estrogen facilitates heat dissipation both by skin vasodilation and by heat-escape behavior. Ovariectomized rats may mimic climacteric hot flushes not only for autonomic skin vasomotor activity but also for thermoregulatory behavior.

Sign in / Sign up

Export Citation Format

Share Document