急性单侧输尿管扩张通过麻醉大鼠体内的γ-氨基丁酸能神经传递抑制谷氨酸依赖性脊髓盆段-尿道反射增强。
Acute unilateral ureteral distension inhibits glutamate-dependent spinal pelvic-urethra reflex potentiation via GABAergic neurotransmission in anesthetized rats.
作者信息
Chen Kuo-Jung, Peng Hsien-Yu, Cheng Chen-Li, Chen Cheng-Hsu, Liao Jiuan-Miaw, Ho Yu-Cheng, Liou Jung-Tong, Tung Kwong-Chung, Hsu Tien-Huan, Lin Tzer-Bin
机构信息
Institute of Medicine, College of Medicine, Chung-Shan Medical University,Taichung, Taiwan.
出版信息
Am J Physiol Renal Physiol. 2007 Mar;292(3):F1007-15. doi: 10.1152/ajprenal.00256.2006. Epub 2006 Nov 22.
The effects of an acute increase in intraureteral pressure (IUP) on pelvic-urethra reflex potentiation were examined in urethane-anesthetized rats by recording the external urethral sphincter electromyogram activities evoked by the pelvic afferent stimulation. Compared with a single action potential elicited by the test stimulation (TS; characterized by an intensity that evoked a constant reflex response without facilitation, 1/30 Hz, 1.03 +/- 0.12 spikes/stimulation, n = 7), the repetitive stimulation [RS; identical stimulation intensity as the TS (1 Hz)] significantly induced spinal reflex potentiation (SRP; 16.90 +/- 2.00 spikes/stimulation, P < 0.01, n = 7). Such SRP was significantly attenuated by intrathecal 2,3-dihydroxy-6-nitro-7-sulfamoyl-benzo (F) quinoxaline [NBQX; a glutamatergic alpha-amino-3-hydroxy-5-methyl-4-isoxazoleproprionat (AMPA) receptor antagonist] and d-2-amino-5-phosphonovalerate [APV; a glutamatergic N-methyl-d-aspartate (NMDA) antagonist; the spike number per stimulation: 11.0 +/- 0.70 for NBQX, 1.01 +/- 0.30 for APV, and 16.90 +/- 2.0 for RS, respectively, n = 7, P < 0.01]. Acute stepwise elevations of IUP gradually attenuated and eventually abolished the RS-induced SRP (16.80 +/- 1.30, 17.00 +/- 1.30, 16.30 +/- 1.30, 10.50 +/- 1.80, 8.80 +/- 1.90, 3.50 +/- 1.60, 0.80 +/- 0.20, 0.70 +/- 0.20, and 0.20 +/- 0.10 spikes/stimulation at intraureteral pressure of 0, 2.5, 5, 7.5, 10, 12.5, 15, 17.5, and 20 cmH(2)O, respectively, n = 7). Intrathecal NMDA (a glutamatergic NMDA receptor agonist) and bicuculline (a GABA receptor antagonist) both reversed the abolition of RS-induced SRP caused by unilateral ureteral distension (14.0 +/- 4.04 and 8.00 +/- 1.53 spikes/stimulation, respectively, n = 7, P < 0.01). All the results suggested unilateral ureteral distension might compensatorily relax the urethra via GABAergic inhibition of NMDA-dependent SRP.
通过记录盆腔传入神经刺激诱发的尿道外括约肌肌电图活动，在氨基甲酸乙酯麻醉的大鼠中研究了输尿管内压（IUP）急性升高对盆腔 - 尿道反射增强的影响。与测试刺激（TS；其特征为强度能诱发恒定反射反应且无易化作用，1/30 Hz，1.03±0.12个峰/刺激，n = 7）引发的单个动作电位相比，重复刺激[RS；与TS相同的刺激强度（1 Hz）]显著诱导脊髓反射增强（SRP；16.90±2.00个峰/刺激，P < 0.01，n = 7）。鞘内注射2,3 - 二羟基 - 6 - 硝基 - 7 - 氨磺酰基 - 苯并（F）喹喔啉[NBQX；一种谷氨酸能α - 氨基 - 3 - 羟基 - 5 - 甲基 - 4 - 异恶唑丙酸（AMPA）受体拮抗剂]和d - 2 - 氨基 - 5 - 磷酸戊酸[APV；一种谷氨酸能N - 甲基 - d - 天冬氨酸（NMDA）受体拮抗剂；每次刺激的峰数分别为：NBQX为11.0±0.70，APV为1.01±0.30，RS为16.90±2.0，n = 7，P < 0.01]可显著减弱这种SRP。IUP的急性逐步升高逐渐减弱并最终消除了RS诱导的SRP（在输尿管内压为0、2.5、5、7.5、10、12.5、15、17.5和20 cmH₂O时，每次刺激的峰数分别为16.80±1.30、17.00±1.30、16.30±1.30、10.50±1.80、8.80±1.90、3.50±1.60、0.80±0.20、0.70±0.20和0.20±0.10个峰/刺激，n = 7）。鞘内注射NMDA（一种谷氨酸能NMDA受体激动剂）和荷包牡丹碱（一种GABA受体拮抗剂）均逆转了单侧输尿管扩张导致的RS诱导的SRP的消除（每次刺激的峰数分别为14.0±4.04和8.00±1.53，n = 7，P < 0.01）。所有结果表明，单侧输尿管扩张可能通过GABA能抑制NMDA依赖的SRP来补偿性地松弛尿道。
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