Functional and morphological effects of β-estradiol in eyes with N-methyl-d-Aspartate-induced retinal neurotoxicity in rats

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• 作者：Haruhiro Yamashita ; ^a ; ^{h.yamashita@po.rd.taisho.co.jp"" rel=""nofollow} ; Chiaki Yamada-Nakayama^a ; Kazunari Sugihara^a ; Satoshi Tsuji^a ; Takanobu Sakurai^a ; Yoshiki Ban^a ; Shunsuke Tsutsumi^a ; Yasushi Sato^a
• 关键词：&#x3b2 ; -estradiol ; N-methyl-d-aspartate ; retinal neurotoxicity ; full-field ERG ; rat
• 刊名：Experimental Eye Research
• 出版年：2011
• 出版时间：July 2011
• 年：2011
• 卷：93
• 期：1
• 页码：75-81
• 全文大小：603 K

文摘

Glutamate-mediated excitotoxicity, mainly induced by N-methyl-d-aspartate (NMDA) receptors, is known to cause retinal ganglion cell death in retinal ischemia, glaucoma, and several other retinal diseases. We evaluated the effects of β-estradiol (E2) against a single intravitreal injection of NMDA using a functional and morphological approach. Male rats were randomly divided into 3 treatment groups: (1) Control; (2) NMDA (intravitreal injection of 5 mM NMDA); and (3) NMDA + E2 (intravitreal injection of 5 mM NMDA and pretreatment with subcutaneous E2 implantation). Seven days after NMDA injection, full-field electroretinograms (ERGs) and quantitative morphological analyses using transverse sections of the retina were conducted. In the NMDA group, full-field ERGs showed reductions in the amplitudes of the negative-scotopic threshold response, rod response b-wave, oscillatory potentials, flicker response second b-wave and cone response b-wave. Morphological evaluations of transverse sections of the retina demonstrated a reduction in the thickness of the inner plexiform layer, increases in the thickness of the outer plexiform and outer nuclear layers, and a loss of cells in the ganglion cell layer. In the NMDA + E2 group, pretreatment with E2 prevented the aggravations in the amplitudes of the ERGs except for oscillatory potential 2 (OP2); however, no morphological differences between the NMDA and NMDA + E2 groups were seen. These findings indicate that E2 can protect retinal function against NMDA-induced neurotoxicity. In addition, these indications suggested that the effect of E2 may have therapeutic benefits in NMDA related diseases, such as retinal ischemia and glaucoma.