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Effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats
The majority of the numerous animal studies of the effects of estrogens on cerebral ischemia have reported neuroprotective results, but a few have shown increased damage. Differences in hormone administration methods, resulting in highly different 17β-estradiol levels, may explain the discrepancies...
Autores principales: | , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
Nature Publishing Group
2016
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4738304/ https://www.ncbi.nlm.nih.gov/pubmed/26839007 http://dx.doi.org/10.1038/srep20228 |
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author | Ingberg, Edvin Theodorsson, Elvar Theodorsson, Annette Ström, Jakob O. |
author_facet | Ingberg, Edvin Theodorsson, Elvar Theodorsson, Annette Ström, Jakob O. |
author_sort | Ingberg, Edvin |
collection | PubMed |
description | The majority of the numerous animal studies of the effects of estrogens on cerebral ischemia have reported neuroprotective results, but a few have shown increased damage. Differences in hormone administration methods, resulting in highly different 17β-estradiol levels, may explain the discrepancies in previously reported effects. The objective of the present study was to test the hypothesis that it is the delivered dose per se, and not the route and method of administration, that determines the effect, and that high doses are damaging while lower doses are protective. One hundred and twenty ovariectomized female Wistar rats (n = 40 per group) were randomized into three groups, subcutaneously administered different doses of 17β-estradiol and subjected to transient middle cerebral artery occlusion. The modified sticky tape test was performed after 24 h and the rats were subsequently sacrificed for infarct size measurements. In contrast to our hypothesis, a significant negative correlation between 17β-estradiol dose and infarct size was found (p = 0.018). Thus, no support was found for the hypothesis that 17β-estradiol can be both neuroprotective and neurotoxic merely depending on dose. In fact, on the contrary, the findings indicate that the higher the dose of 17β-estradiol, the smaller the infarct. |
format | Online Article Text |
id | pubmed-4738304 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2016 |
publisher | Nature Publishing Group |
record_format | MEDLINE/PubMed |
spelling | pubmed-47383042016-02-09 Effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats Ingberg, Edvin Theodorsson, Elvar Theodorsson, Annette Ström, Jakob O. Sci Rep Article The majority of the numerous animal studies of the effects of estrogens on cerebral ischemia have reported neuroprotective results, but a few have shown increased damage. Differences in hormone administration methods, resulting in highly different 17β-estradiol levels, may explain the discrepancies in previously reported effects. The objective of the present study was to test the hypothesis that it is the delivered dose per se, and not the route and method of administration, that determines the effect, and that high doses are damaging while lower doses are protective. One hundred and twenty ovariectomized female Wistar rats (n = 40 per group) were randomized into three groups, subcutaneously administered different doses of 17β-estradiol and subjected to transient middle cerebral artery occlusion. The modified sticky tape test was performed after 24 h and the rats were subsequently sacrificed for infarct size measurements. In contrast to our hypothesis, a significant negative correlation between 17β-estradiol dose and infarct size was found (p = 0.018). Thus, no support was found for the hypothesis that 17β-estradiol can be both neuroprotective and neurotoxic merely depending on dose. In fact, on the contrary, the findings indicate that the higher the dose of 17β-estradiol, the smaller the infarct. Nature Publishing Group 2016-02-03 /pmc/articles/PMC4738304/ /pubmed/26839007 http://dx.doi.org/10.1038/srep20228 Text en Copyright © 2016, Macmillan Publishers Limited http://creativecommons.org/licenses/by/4.0/ This work is licensed under a Creative Commons Attribution 4.0 International License. The images or other third party material in this article are included in the article’s Creative Commons license, unless indicated otherwise in the credit line; if the material is not included under the Creative Commons license, users will need to obtain permission from the license holder to reproduce the material. To view a copy of this license, visit http://creativecommons.org/licenses/by/4.0/ |
spellingShingle | Article Ingberg, Edvin Theodorsson, Elvar Theodorsson, Annette Ström, Jakob O. Effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats |
title | Effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats |
title_full | Effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats |
title_fullStr | Effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats |
title_full_unstemmed | Effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats |
title_short | Effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats |
title_sort | effects of high and low 17β-estradiol doses on focal cerebral ischemia in rats |
topic | Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4738304/ https://www.ncbi.nlm.nih.gov/pubmed/26839007 http://dx.doi.org/10.1038/srep20228 |
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