Estrogen Can Act via Estrogen Receptor (cid:1) and (cid:2) to Protect Hippocampal Neurons against Global Ischemia-Induced Cell Death
Estrogen Can Act via Estrogen Receptor (cid:1) and (cid:2) to Protect Hippocampal Neurons against Global Ischemia-Induced Cell Death
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DOI:
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发表时间:
2005
影响因子:
1.1
通讯作者:
N. R. Miller;T. Jover;Hillel W. Cohen;R. Zukin;A. M. Etgen
中科院分区:
文献类型:
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作者:
N. R. Miller;T. Jover;Hillel W. Cohen;R. Zukin;A. M. Etgen
Estradiol at physiological concentrations intervenes in apo- ptotic death cascades and ameliorates neuronal death in experimental models of focal and global ischemia. The cellular targets that mediate estradiol protection of hippocampal neurons in global ischemia are, however, unclear. The present study examined the hypothesis that estradiol protects hippocampal neurons in ovariectomized rats via estrogen recep- tor (ER) (cid:1) and/or (cid:2) . Estradiol (14 d pretreatment) afforded robust protection of CA1 neurons against global ischemia-induceddeath.Thebroad-spectrumERantagonistICI182,780(intracerebroventricularly,0and12hafterischemia)abol-ishedestrogenprotection,consistentwitharoleforERs.ToevaluatethepotentialrolesofER (cid:1) vs. ER (cid:2) in estrogen pro- tection, we administered subtype-selective agonists for 14 d before and 7 d after ischemia. The ER (cid:1) -selective agonist propyl pyrazole triol (PPT, 10 mg/kg) and ER (cid:2) -selective agonist WAY 200070–3 (1 mg/kg) produced nearly complete protection of CA1 neurons in approximately 50% of the animals. PPT, but not WAY 200070–3, at doses used for protection, elicited lor-dosis,inducednegativefeedbackinhibitionofLHrelease,andreducedweightgain.ThesefindingsestablishtheefficacyofthePPTdoseinneuroendocrineassaysandspecificityofWAY200070–3forER (cid:2) . We also examined the ability of estradiol and neuronal injury to regulate ER (cid:1) and ER (cid:2) expression. Both estradiol and global ischemia markedly increased ER (cid:1) , butnotER (cid:2) ,proteininCA1.Thesedataindicatethatestradiol can act via ER (cid:1) and ER (cid:2) to protect CA1 neurons from global ischemia-induced death and that both estradiol and global ischemia modulate ER (cid:1) expression in hippocampal CA1. En- the specificity performed independent physiological