雌激素調節麻醉老鼠脊髓NMDA接受器調控骨盆神經到尿道反射的可塑性

林則彬林勝彥Sheng-Yen醫學研究所2026-10-289999-12-312007https://handle.ncl.edu.tw/11296/4tx4kshttps://scholars.csmu.edu.tw/handle/123456789/35231背景：雌激素對於NMDA接受器 (N-methyl-D-aspartic acid receptor) 調節排尿 (micturition) 功能的作用，可以經由骨盆神經到尿道反射 (pelvic nerve-to-urethra reflex，PUR) 的可塑性 (plasticity) 來加以研究，此種可塑性可以藉由對雌性老鼠進行假手術 (Sham operation，Sham)、卵巢摘除術 (ovariectomy，OVX)、或卵巢摘除術併行每日補充17 β-estradiol (50 µg/kg，OVX + E2) 以後，施以重複刺激 (repetitive stimulation，RS，1 Hz) 骨盆神經而激發。方法：研究期間是從2004年3月至2005年6月。實驗動物是使用雌性Sprague Dawley大白鼠63隻，隨機分派成3組 (Sham，OVX，和 OVX + E2)，每組21隻老鼠。每隻老鼠從脊椎管內分別注射normal saline，L-glutamate，NMDA (N-methyl-D-aspartic acid)，NBQX ( 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo (F) quinoxaline ) 和APV ( D-2-amino-5-phosphonovaleric acid ) 以後，試驗刺激與重複刺激骨盆神經，紀錄外尿道括約肌的動作電位。所有實驗數據的計算都採用平均數 ± 平均數的標準誤 (mean ± SEM.)，實驗數據的統計分析則採用變異數分析 (ANOVA)。若p < 0.05，則被認為在統計學上有顯著的差異。結果：跟Sham組和OVX + E2組比較，對OVX組的老鼠，重複刺激所誘發之PUR活性增強 (potentiation) 的強度呈現顯著減少 (Sham，OVX，和OVX + E2 組分別為18.09 ± 3.91，7.40 ± 1.03，和12.60 ± 1.49動作電位數/刺激 (spikes/stimu- lation)； p < 0.01， n = 21)；但是在Sham組與OVX + E2組之間，沒有統計學上顯著差異 ( p > 0.05， n = 21)。然而，在脊椎管內注射NBQX (20 µM，10 µl) 以後，重複刺激所誘發之PUR活性增強的強度，三組皆呈現顯著減少 (Sham，OVX，和OVX + E2 組分別為從18.09 ± 3.91減到10.40 ± 0.81，從 7.40 ± 1.03減到3.20 ± 0.94，和從12.60 ± 1.49減到8.06 ± 0.32動作電位數/刺激； p < 0.01， n = 18)；但是在脊椎管內注射APV (100 µM，10 µl) 以後，重複刺激所誘發之PUR活性增強的強度，三組皆呈現顯著阻斷 (Sham，OVX，和OVX + E2 組分別為從18.09 ± 3.91減到1.04 ± 0.12，從7.40 ± 1.03減到1.06 ± 0.22，和從12.60 ± 1.49減到0.98 ± 0.25動作電位數/刺激； p < 0.01，n = 18)。另外，在脊椎管內注射L-麩胺酸 (L-glutamate， 0.1mM，10 µl) 以後，試驗刺激 (TS，1/30 Hz) 所誘發之PUR活性增強的強度，三組皆呈現顯著增加 (Sham，OVX，和OVX + E2 組分別為從1.04 ± 0.02增到21.60 ± 0.93，從1.10 ± 0.06增到8.40 ± 1.50，和從1.03 ± 0.03增到18.04 ± 0.84動作電位數/刺激； p < 0.01，每組n = 18)。在脊椎管內注射 N-甲基-D-天門冬胺酸 (NMDA， 0.1 mM，10 µl) 以後，試驗刺激所誘發之PUR活性增強的強度，三組也都呈現顯著增加 (Sham, OVX，和OVX + E2 組分別為從1.04 ± 0.02增到14.80 ± 0.97，從1.10 ± 0.06增到4.60 ± 0.48，和從1.03 ± 0.03增到9.09 ± 0.63動作電位數/刺激； p < 0.01， n = 18)。結論：這些數據顯示雌激素可以調節雌性老鼠脊髓NMDA接受器調控骨盆神經到尿道反射的可塑性。雌性老鼠被摘除雙側卵巢以後，會引起老鼠體內雌激素缺乏 (estrogen deficiency )，然後導致老鼠下泌尿道功能異常 (lower urinary tract dysfunction， LUTD)，最後可能引發應力性尿失禁 (stress urinary incontinence，SUI) 的許多症狀。Background: The effects of estrogen on NMDA (N-methyl-D-aspartic acid) receptor- mediated pelvic nerve-to-urethra reflex (PUR) plasticity were investigated in rats, which received a sham operation (Sham), an ovariectomy (OVX) or an ovariectomy with daily supplemental 17 β-estradiol (50 μg/kg, OVX + E2).Methods: The study period was from March 1, 2004 to June 30, 2005. 63 adult female Sprague Dawley rats were used as experimental animals. The rats were randomly divided into 3 groups (Sham, OVX, and OVX + E2). Each group had 21 rats. Test stimulation and repetitive stimulation were applied to the pelvic nerve following intrathecal injections of normal saline, L-glutamate, NMDA ( N-methyl-D-aspartic acid), NBQX ( 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo (F) quinoxaline ), and APV (D-2-amino-5-phosphonovaleric acid). External urethral sphincter action potentials were recorded. All the data in the text and figures were mean ± SEM. Statistical analysis of the data was performed with ANOVA. A value of less than 0.05 was considered statistically significant difference.Results: The magnitude of the repetitive stimulation (RS, 1 Hz)-induced potentiation in PUR activity decreased significantly in the OVX group when compared with the Sham groups (18.09 ± 3.91 and 7.40 ± 1.03 spikes / stimulation in Sham and OVX groups respectively, p < 0.01, n = 21). Supplemental 17 β-estradiol (OVX + E2, 12.60 ± 1.49 spikes/ stimulation) significantly reversed the decrease in RS-induced PUR potentiation caused by OVX (p < 0.01, n = 21). The magnitude of the RS-induced potentiation in PUR activity decreased significantly after intrathecal NBQX (20 μM, 10 μl, from 18.09 ± 3.91 to 10.40 ± 0.81, from 7.40 ± 1.03 to 3.20 ± 0.94 and from 12.60 ± 1.49 to 8.06 ± 0.32 spikes / stimulation in Sham, OVX and OVX + E2 respectively, p < 0.01, n = 18) and APV (100 μM, 10 μl, from 18.09 ± 3.91 to 1.04 ± 0.12, from 7.40 ± 1.03 to 1.06 ± 0.22 and from 12.60 ± 1.49 to 0.98 ± 0.25 spikes / stimulation in Sham, OVX and OVX + E2 respectively, p < 0.01, n = 18). In addition, potentiation in PUR activities was induced by intrathecal L-glutamate (0.1 mM, 10 μl, from 1.04 ± 0.02 to 21.60 ± 0.93, from 1.10 ± 0.06 to 8.40 ± 1.50, and from 1.03 ± 0.03 to 18.04 ± 0.84 spikes / stimula tion in Sham, OVX and OVX + E2 respectively, p < 0.01, n = 18) and NMDA (0.1 mM, 10 μl, from 1.04 ± 0.02 to 14.80 ± 0.97, from 1.10 ± 0.06 to 4.60 ± 0.48, and from 1.03 ± 0.03 to 9.09 ± 0.63 spikes / stimulation in Sham, OVX and OVX + E2 respectively, p < 0.01, n = 18).Conclusions: The present data suggests that estrogen modulates spinal cord NMDA receptor-mediated PUR plasticity in female rats. Estrogen deficiency may contribute to lower urinary tract dysfunction (LUTD) after bilateral ovariectomy of female rats. Consequently, symptoms of stress urinary incontinence (SUI) may be encountered.雌激素調節麻醉老鼠脊髓NMDA接受器調控骨盆神經到尿道反射的可塑性thesis