Alteration by urethane of glutamatergic control of micturition.
Alteration by urethane of glutamatergic control of micturition.
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DOI：
10.1016/0014-2999(94)00505-2
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发表时间：
1994-11
影响因子：
5
通讯作者：
M. Yoshiyama;J. Roppolo;W. C. Groat
中科院分区：
文献类型：
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作者：
M. Yoshiyama;J. Roppolo;W. C. Groat
静脉注射MK-801（0.001 - 3 mg/kg），一种非竞争性NMDA受体拮抗剂，在快速输注（0.21 ml/min）膀胱测压或等容条件下记录的未麻醉去大脑大鼠中没有改变反射性膀胱活动，但在麻醉大鼠（1.2 g/kg s.c.）中，0.1 - 3 mg/kg i. v.剂量确实抑制反射性膀胱收缩。完整大鼠快速输注膀胱测压。在麻醉的完整大鼠中，ED 50和产生最大抑制的剂量分别为0.25 mg/kg和3 mg/kg i. v.，分别在缓慢输注（0.04 ml/min）膀胱测压期间，在未麻醉的去大脑大鼠中，MK-801（0.1-1 mg/kg i. v.或6-60 μg i.t.）使排尿量阈值（VT）降低12-44%，但不改变膀胱收缩的幅度和持续时间。管理一个更大的信息技术。MK-801（60 μg）不能进一步降低VT，但使膀胱收缩幅度降低24%。MK-801（0.01-3 mg/kg i.v.）在未麻醉的去脑大鼠和麻醉的完整大鼠中，ED_（50）分别为0.12 mg/kg和0.05 mg/kg。这些结果表明，NMDA受体在促进和抑制排尿功能的中枢神经控制中起着重要作用，并且乌拉坦麻醉和NMDA受体介导的传递之间存在着显著的相互作用。因此，尽管乌拉坦麻醉对研究排尿反射的生理特征是有用的，但它似乎不适合分析谷氨酸在反射性排尿中的正常递质作用。
The i.v. administration of MK-801 (0.001−3 mg/kg), a non-competitive NMDA receptor antagonist, did not alter reflex bladder activity in unanesthetized decerebrate rat recorded during fast infusion (0.21 ml/min) cystometry or under isovolumetric conditions, but did depress reflex bladder contractions in doses between 0.1 and 3 mg/kg i.v. in the urethane-anesthetized (1.2 g/kg s.c.) intact rat during fast infusion cystometry. The ED50and the dose to produce maximal inhibition in urethane-anesthetized intact rats were 0.25 mg/kg and 3 mg/kg i.v., respectively. During slow infusion (0.04 ml/min) cystometry, in unanesthetized decerebrate rats, MK-801 (0.1–1 mg/kg i.v. or 6–60 μg i.t.) decreased by 12–44% the micturition volume threshold (VT) but did not change the amplitude and duration of the bladder contractions. The administration of a larger i.t. dose (60 μg) of MK-801 produced no further decrease inVTbut decreased the amplitude of bladder contractions by 24%. External urethral sphincter electromyogram activity was reduced or abolished by MK-801 (0.01–3 mg/kg i.v.) in both unanesthetized decerebrate and urethane-anesthetized intact rats with ED50of 0.12 mg/kg and 0.05 mg/kg, respectively. These results indicate that NMDA receptors play an important role in both facilitatory and inhibitory central neural control of voiding function and that there is a significant interaction between urethane anesthesia and NMDA glutamatergic transmission. Thus, even though urethane anesthesia has been useful for studying the physiological characteristics of the micturition reflex, it seems inappropriate for analyzing the normal transmitter role of glutamic acid in reflex voiding.