Role of pudendal afferents in voiding efficiency in the rat
Role of pudendal afferents in voiding efficiency in the rat
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DOI：
10.1152/ajpregu.00270.2007
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发表时间：
2008-02-01
影响因子：
2.8
通讯作者：
Grill, Warren M.
中科院分区：
文献类型：
--
作者：
Peng, Chih-Wei;Chen, Jia-Jin Jason;Grill, Warren M.
膀胱和尿道外括约肌（EUS）的相互活动由来自脑桥排尿中心的下行投射协调，但受到外周传入输入的调节。横断支配横纹EUS的躯体阴部神经，大鼠排尿效率降低，残尿增多。排尿效率的降低是由于去神经支配后EUS缺乏相性破裂活动。然而，阴部神经的横断也消除了可能在排尿中起作用的躯体感觉反馈。我们假设来自阴部传入神经的反馈是有效排尿所必需的，阴部感觉活动的丧失导致了阴部神经横断后排尿效率的降低。在选择性切除阴部神经分支、化学调节尿道传入活动和神经肌肉阻断后，经氨基甲酸乙酯麻醉的雌性大鼠的定量膀胱测量显示，阴部神经传入有助于有效排尿。感觉反馈增强了膀胱收缩的幅度和持续时间，从而增加了排尿的驱动力。其次，感觉反馈对于膀胱收缩时EUS活动的交替爆发和静止是必要的。这些发现表明阴部感觉活动的丧失有助于阴部神经横断后观察到的排尿效率降低，并说明尿道感觉反馈在调节膀胱功能中的重要性。
The reciprocal activities of the bladder and external urethral sphincter (EUS) are coordinated by descending projections from the pontine micturition center but are subjected to modulation by peripheral afferent inputs. Transection of the somatic pudendal nerve innervating the striated EUS decreases voiding efficiency and increases residual urine in the rat. The reduction in voiding efficiency was attributed to the lack of phasic bursting activity of the EUS following denervation. However, transection of the pudendal nerve also eliminates somatic sensory feedback that may play a role in voiding. We hypothesized that feedback from pudendal afferents is required for efficient voiding and that the loss of pudendal sensory activity contributes to the observed reduction in voiding efficiency following pudendal nerve transection. Quantitative cystometry in urethane anesthetized female rats following selective transection of pudendal nerve branches, following chemical modulation of urethral afferent activity, and following neuromuscular blockade revealed that pudendal nerve afferents contributed to efficient voiding. Sensory feedback augmented bladder contraction amplitude and duration, thereby increasing the driving force for urine expulsion. Second, sensory feedback was necessary to pattern appropriately the EUS activity into alternating bursts and quiescence during the bladder contraction. These findings demonstrate that the loss of pudendal sensory activity contributes to the reduction in voiding efficiency observed following pudendal nerve transection, and illustrate the importance of urethral sensory feedback in regulating bladder function.