Rectal distention inhibits bladder activity via glycinergic and gabaergic mechanisms in rats
Rectal distention inhibits bladder activity via glycinergic and gabaergic mechanisms in rats
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DOI：
10.1097/01.ju.0000099840.09816.22
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发表时间：
2004-03-01
影响因子：
6.6
通讯作者：
Ogawa, Y
中科院分区：
文献类型：
--
作者：
Miyazato, M;Sugaya, K;Ogawa, Y
目的：我们研究了直肠扩张对脊髓延髓排尿反射的影响和抑制膀胱contraction.Materials和方法的机制：共22只雌性SD大鼠在这项研究中使用。用尿烷麻醉，在直肠球囊扩张前后进行等容膀胱测压（0至3 cm（3）），然后鞘内注射士的宁（甘氨酸受体拮抗剂，0.001 - 10 μ g）和/或荷包牡丹碱（一种γ-氨基丁酸（A）受体拮抗剂，0.001 - 1 μ g）。结果：直肠扩张（1.5 ~ 3.0cm3）使膀胱收缩间期延长，幅度降低，持续时间缩短，最后几乎完全消失。在直肠扩张抑制膀胱的动物中，鞘内注射士的宁或荷包牡丹碱后，膀胱收缩的间隔和持续时间恢复到基线水平，但幅度仅恢复到对照水平的47%~ 54%。然而，同时鞘内注射士的宁和荷包牡丹碱（各0.001 μ g）恢复振幅到对照水平。士的宁和荷包牡丹碱对膀胱收缩的间期、幅度和持续时间的影响无差异。结论：大鼠腰骶髓存在抑制性直肠膀胱反射。脊髓延髓排尿反射通路的传入支可能被甘氨酸能和GABA能机制额外和冗余地抑制，而该通路的传出支可能被这些机制协同抑制。
Purpose: We examined the influence of rectal distention on the spinobulbospinal micturition reflex and the mechanism underlying the inhibition of bladder contraction.Materials and Methods: A total of 22 female Sprague-Dawley rats were used in this study. Using urethane anesthesia isovolumetric cystometry was performed before and after distention of the rectum by inflation of a rectal balloon (0 to 3 cm(3)), followed by the intrathecal injection of strychnine (a glycine receptor antagonist, 0.001 to 10 mug) and/or bicuculline (a gamma-aminobutyric acid(A) receptor antagonist, 0.001 to 1 mug) at the lumbosacral level of the spinal cord.Results: Rectal distention (1.5 to 3.0 cm(3)) prolonged the interval, decreased the amplitude and shortened the duration of bladder contraction and finally almost abolished bladder activity. After intrathecal injection of strychnine or bicuculline in animals with inhibition of the bladder by rectal distention the interval and duration of bladder contraction returned to baseline but amplitude only recovered to 47% to 54% of the control level. However, simultaneous intrathecal injection of strychnine and bicuculline (0.001 mug each) restored amplitude to the control level. There were no differences between strychnine and bicuculline with respect to their effects on the interval, amplitude and duration of bladder contraction.Conclusions: An inhibitory rectovesical reflex exists in the lumbosacral cord of rats. The afferent limb of the spinobulbospinal micturition reflex pathway may be additionally and redundantly inhibited by glycinergic and GABAergic mechanisms, while the efferent limb of this pathway may be synergistically inhibited by these mechanisms.