Apigenin acts as a partial agonist action at estrogen receptors in vivo

2021 ◽  
pp. 174175
Author(s):  
Lu Yao ◽  
Zhuoyan Fan ◽  
Shiwen Han ◽  
Na Sun ◽  
Huilian Che
Keyword(s):  
Estrogen Receptors ◽  
Partial Agonist ◽  
Agonist Action

Identifying potential PPARγ agonist/partial agonist from plant molecules to control type 2 diabetes using in silico and in vivo models

2016 ◽  
Vol 25 (9) ◽  
pp. 1980-1992 ◽  
Author(s):  
Antony Stalin ◽  
Santiagu Stephen Irudayaraj ◽  
Dhandapani Ramesh Kumar ◽  
Kedike Balakrishna ◽  
Savarimuthu Ignacimuthu ◽  
...  
Keyword(s):  
Type 2 Diabetes ◽  
In Silico ◽  
Partial Agonist ◽  
In Vivo Models ◽  
Pparγ Agonist

scholarly journals Estrogen-Like Activity of Perfluoroalkyl Acids In Vivo and Interaction with Human and Rainbow Trout Estrogen Receptors In Vitro

2010 ◽  
Vol 120 (1) ◽  
pp. 42-58 ◽  
Author(s):  
Abby D. Benninghoff ◽  
William H. Bisson ◽  
Daniel C. Koch ◽  
David J. Ehresman ◽  
Siva K. Kolluri ◽  
...  
Keyword(s):  
Rainbow Trout ◽  
Estrogen Receptors ◽  
Perfluoroalkyl Acids

Mechanism of Action of Progestins in the Treatment of Hormone-dependent Breast Cancer.

1975 ◽  
Vol 61 (6) ◽  
pp. 501-508 ◽  
Author(s):  
Francesco Di Carlo ◽  
Giovanni Pacilio ◽  
Giuseppe Conti
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptors ◽  
Mechanism Of Action ◽  
Mode Of Action ◽  
Binding Capacity ◽  
Specific Receptors ◽  
High Concentrations ◽  
Good Agreement

The in vitro interference of some gestagens with the binding of 3H-17 β-oestradiol to cytosol specific receptors was investigated with a view to elucidating the mechanism of action of progestins in the treatment of human hormone-dependent breast cancer. A decrease (up to 85 %) of oestradiol binding capacity was observed with high concentrations of progesterone, clogestone and medrogestone. These findings are in good agreement with those previously obtained by the same progestins in our laboratory on rat uterine estrogen receptors in vitro or in vivo. These results provide support for the hypothesis that the mode of action of progestins in the therapy of mammary and perhaps uterine carcinomas is to some extent related to the inhibition of oestradiol binding to cytosol specific receptors.

Asenapine reduces anxiety-related behaviours in rat conditioned fear stress model

2016 ◽  
Vol 28 (6) ◽  
pp. 327-336 ◽  
Author(s):  
Masayo Ohyama ◽  
Maho Kondo ◽  
Miki Yamauchi ◽  
Taiichiro Imanishi ◽  
Tsukasa Koyama
Keyword(s):  
Receptor Antagonist ◽  
Partial Agonist ◽  
Conditioned Fear ◽  
Serotonin Release ◽  
Rat Hippocampus ◽  
Stress Model ◽  
Electrical Shock ◽  
Conditioned Fear Stress ◽  
Skinner Box

ObjectiveAsenapine is an atypical antipsychotic that is currently available for the treatment of schizophrenia and bipolar I disorder. Although the atypical antipsychotics clozapine and olanzapine are effective for depression and anxiety in schizophrenia, as demonstrated by animal model studies, this has not been clarified for asenapine. Therefore, we compared the effects of asenapine in the conditioned fear stress model with those of clozapine and olanzapine.MethodRats were individually fear conditioned using electrical foot shock in a Skinner box. Approximately 24 h later, individual animals were returned to the same Skinner box (without electrical shock) and their freezing behaviour was observed for 5 min. Animals were treated with asenapine, clozapine, olanzapine, the 5-HT1A receptor partial agonist buspirone, or the 5-HT2C receptor antagonist SB242084 at 30 min before freezing behaviour assessment. The 5-HT1A receptor antagonist WAY100635 or the 5-HT2C receptor agonist Ro60-0175 was also used concomitantly with asenapine. The effects of asenapine, clozapine, and olanzapine on serotonin release in the rat hippocampus were also measured using in vivo microdialysis.ResultsAsenapine reduced freezing behaviour, while neither clozapine nor olanzapine reduced freezing behaviour. Buspirone and SB242084 also reduced freezing behaviour. The effect of asenapine in reducing freezing behaviour was not altered by the concomitant administration of WAY100635 or Ro60-0175. Both asenapine and clozapine, but not olanzapine, increased serotonin release in the rat hippocampus.ConclusionAsenapine may have superior therapeutic effect on anxiety symptoms than other agents, although the underlying mechanism of its anxiolytic activity remains unknown.

The Influence of 17-Oxo- and 17-Hydroxy-16,17-secoestratriene Derivatives on Estrogen Receptor

2006 ◽  
Vol 71 (4) ◽  
pp. 532-542 ◽  
Author(s):  
Suzana Jovanović-Šanta ◽  
Julijana Petrović ◽  
Marija Sakač ◽  
Zorica Žakula ◽  
Esma Isenović ◽  
...  
Keyword(s):  
Estrogen Receptor ◽  
Estrogen Receptors ◽  
Estrogenic Activity ◽  
Total Loss ◽  
The Other ◽  
Binding Parameters ◽  
Antiestrogenic Activity ◽  
Other Hand

Since many of newly synthesised D-secoestratriene derivatives showed antiestrogenic effect, with almost a total loss of estrogenic activity, we studied the effects of some of these compounds on estrogen receptors (ER), the translocation of the estrogen-ER complexes formed in presence of competing substances into the nucleus, as well as the binding of these complexes to DNA. The results of uterotrophic effects of analysed derivatives are in agreement with the influence of these compounds on activity and binding parameters of estrogen receptors. Namely, compounds that show relatively high antiestrogenic activity predominantly increase Kd and inhibit translocation to nuclei of radioactive complexes formed in their presence. On the other hand, compounds that do not significantly change binding parameters of estrogen receptors do not show antiestrogenic effect in in vivo experiments.

Transcriptional activation of the estrogen receptor

1993 ◽  
Vol 39 (2) ◽  
pp. 341-345 ◽  
Author(s):  
L L Wei
Keyword(s):  
Breast Cancer ◽  
Estrogen Receptor ◽  
Estrogen Receptors ◽  
Transcriptional Activation ◽  
Breast Cancer Cells ◽  
Wild Type ◽  
Resistant Phenotype ◽  
Estrogen Receptor Positive ◽  
Almost All

Abstract Almost all breast cancer tumors progress to a hormone-resistant state. Evidence is presented that the existence of mutant estrogen receptors may explain some hormone-resistant phenotypes. Breast tumor cells bearing a mutant receptor that is constitutively active and does not bind hormone would have unregulated cell growth and thus appear to be hormone-independent. Alternatively, breast cancer cells may contain estrogen receptors that are transcriptionally inactive but when co-expressed with wild-type receptors render normal estrogen receptors inactive. These cells would be considered estrogen receptor-positive but would be hormone-resistant. The hormone-resistant phenotype could be further complicated by the finding that other nonreceptor proteins may also modulate the transcriptional activity of estrogen receptors. These findings, if substantiated in vivo, could add to the complexity of the hormone-resistant phenotype. Different strategies of treatment will need to be developed to effectively treat the various subtypes of hormone-resistant breast tumors.

Effect of calcitonin on urine concentration in the rat

1983 ◽  
Vol 244 (4) ◽  
pp. F432-F435 ◽  
Author(s):  
S. Carney ◽  
T. Morgan ◽  
C. Ray ◽  
L. Thompson
Keyword(s):  
Water Permeability ◽  
Partial Agonist ◽  
Collecting Duct ◽  
Free Water ◽  
Urine Concentration ◽  
Distal Nephron ◽  
Free Water Clearance ◽  
Normal Increase

Because mammalian distal nephron segments with both calcitonin- and antidiuretic hormone- (ADH) sensitive adenylate cyclase activity have been described, in vivo and in vitro experiments were performed to study the effect of calcitonin on rat distal nephron water permeability. Calcitonin 1 and 0.1 U/ml, but not 0.01 U/ml, significantly increased the diffusional water permeability in the isolated papillary collecting duct by 15 and 11%, respectively. However, this effect was small when compared with a 68% increase with a supramaximal concentration of ADH (from 4.0 +/- 0.3 to 6.7 +/- 0.9 microns/s; n = 6, P less than 0.01). The normal increase in water permeability with increasing concentration of ADH (0.02 and 0.2 mU/ml) was depressed by the previous addition of calcitonin (1 U/ml) to the bath but was unaltered with the supramaximal ADH concentration (2 mU/ml). Verapamil, a compound that antagonizes cellular calcium entry, did not alter the effect of calcitonin on diffusional water permeability. Calcitonin in concentrations of 0.05, 0.5, and 5 U/ml produced a significant reduction in urine flow and free water clearance. Pretreatment with calcitonin in these concentrations inhibited the antidiuretic action of ADH. These studies suggest that calcitonin acts as a partial agonist to ADH within the distal nephron. It is unclear whether such an action represents a physiological or a pharmacological effect.

In Vivo Characterization and Dynamic Receptor Occupancy Imaging of TPA023B, an α2/α3/α5 Subtype Selective γ-Aminobutyric Acid–A Partial Agonist

2008 ◽  
Vol 64 (2) ◽  
pp. 153-161 ◽  
Author(s):  
Koen Van Laere ◽  
Guy Bormans ◽  
Sandra M. Sanabria-Bohórquez ◽  
Tjibbe de Groot ◽  
Patrick Dupont ◽  
...  
Keyword(s):  
Partial Agonist ◽  
Receptor Occupancy ◽  
Aminobutyric Acid ◽  
In Vivo Characterization ◽  
Subtype Selective
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