Activation of α1D adrenergic receptors in the rat urothelium facilitates the micturition reflex
Activation of α1D adrenergic receptors in the rat urothelium facilitates the micturition reflex
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DOI：
10.1016/s0022-5347(05)00016-9
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发表时间：
2006-01-01
影响因子：
6.6
通讯作者：
Kawatani, M
中科院分区：
文献类型：
--
作者：
Ishihama, H;Momota, Y;Kawatani, M
目的：以往的研究表明，尿路上皮细胞α 1肾上腺素能受体的激活释放神经递质。我们确定，如果α，肾上腺素能受体表达在大鼠膀胱尿道，如果这些受体的抑制影响反射voiding.Materials和方法：雌性Wistar大鼠在实验中使用。通过Western blot评估受体表达。受体激活的影响进行了研究，使用cystometrogranules，测量三磷酸腺苷浓度在膀胱腔和传入神经记录。结果：Westernblot和免疫组化检测到α 1肾上腺素能受体在尿路上皮组织中的表达。在清醒大鼠连续灌注膀胱测压中，萘哌地尔使收缩间期延长（对照值的143%），并抑制膀胱内灌注醋酸（0.1%）对收缩间期的兴奋作用（220%）。萘哌地尔抑制膀胱扩张（32.0%）和醋酸灌注（30.4%）引起的膀胱传入神经活动，并降低在膀胱扩张（36.6%）的膀胱灌注液中的腺苷三磷酸水平。结论：内源性儿茶酚胺似乎作用于α（1D）受体在尿路促进机械敏感性膀胱传入神经活动和反射排尿。
Purpose: Previous studies have revealed that the activation of a, adrenergic receptors in urothelial cells releases neurotransmitters. We determined if a,, adrenergic receptors are expressed in the urothelium of the rat bladder and if inhibition of these receptors affects reflex voiding.Materials and Methods: Female Wistar rats were used in the experiments. Receptor expression was evaluated by Western blot. The effects of receptor activation were studied using cystometrograins, measurement of adenosine triphosphate concentrations in the bladder lumen and afferent nerve recording. The alpha(1D) antagonist naftopidil (0.75 to 1.66 mg/kg) was administered intravenously into the external jugular vein.Results: The expression of a,, adrenergic receptors was detected in urothelial tissue with Western blot and immunohistochemistry. The all) receptor antagonist naftopidil prolonged the intercontraction interval during continuous infusion cystometrograms in conscious rats (143% of the control value) and suppressed the excitatory effect of intravesical infusion of acetic acid (0.1%) on the intercontraction interval (220%). Naftopidil inhibited the bladder afferent nerve activity induced by bladder distention (32.0%) and acetic acid infusion (30.4%), and decreased adenosine triphosphate levels in the bladder perfusate during bladder distention (36.6%).Conclusions: Endogenous catecholamines appear to act on alpha(1D) receptors in the urothelium to facilitate mechanosensitive bladder afferent nerve activity and reflex voiding.