Morrison J F, Sato A, Sato Y, Yamanishi T
Department of Physiology, University of Leeds, United Kingdom.
Neurosci Res. 1995 Sep;23(2):195-205. doi: 10.1016/0168-0102(95)00942-m.
(1) Somato-visceral and viscero-visceral reflex interactions have been studied in the bladder branches of the pelvic nerve and in the electromyographic (EMG) activity of the periurethral skeletal muscles of the anesthetized rat, and by observations of changes in bladder motility. (2) Slow distensions of the bladder caused some elevation of intravesical pressure, and culminated in a micturition contraction. Periurethral EMG activity increased gradually during the bladder distension, and showed an oscillatory marked increase during the bladder contraction. There was a small increase in pelvic nerve efferent activity during slow distension, and there was a substantial increase before, or at the start, of a micturition contraction. (3) Oscillatory bursting activity occurred in recordings of the EMG activity from periurethral skeletal muscle during the rising phase of micturition contraction; this was particularly so during the most rapid rise in intravesical pressure, and periods of electrical silence lasting 80-270 ms alternated with bursts of activity in the periurethral EMG. (4) In the present experiments, the switching mechanism activated by pelvic afferent signals related to intravesical pressure reversed the behavior of a number of reflex pathways. When the bladder pressure was low, nociceptive pinching of the perineal skin usually caused bladder contraction and a rise in pelvic nerve efferent activity and in periurethral EMG activity. When the bladder was full, micturition contractions were present and reduced in size and frequency by pinching of the perineal skin. The pelvic nerve efferent activity was correspondingly reduced, while the EMG activity increased during and following the nociceptive stimulus. Cooling the scrotal skin with ice also decreased the frequency of bladder contractions. (5) When the bladder pressure was low, distension of the anus and colon increased periurethral EMG activity, but did not affect bladder tone. However, when the bladder was full, these stimuli reduced the size and frequency of bladder contractions, associated with a reduction in the pelvic nerve efferent activity. There was usually a simultaneous reduction in the EMG activity in periurethral muscles. Similar results were obtained during distension of the seminal vesicles or vagina, or following injection of 20-60 microliters of saline into the lumen of the vas deferens. Reversal of the responses at extremes of intravesical pressure was observed in every case. (6) Following spinal transection at the upper cervical or thoracic level, micturition contractions were absent at high bladder volumes. However the effects described when the neuraxis was intact and the bladder pressure was low were still observed.(ABSTRACT TRUNCATED AT 400 WORDS)
（1）已在麻醉大鼠的盆神经膀胱分支、尿道周围骨骼肌的肌电图（EMG）活动以及通过观察膀胱运动变化，对躯体 - 内脏和内脏 - 内脏反射相互作用进行了研究。（2）膀胱缓慢扩张会导致膀胱内压有所升高，并最终引发排尿收缩。在膀胱扩张过程中，尿道周围EMG活动逐渐增加，并在膀胱收缩期间呈现出振荡性的显著增加。在缓慢扩张期间，盆神经传出活动有小幅增加，而在排尿收缩之前或开始时则有大幅增加。（3）在排尿收缩上升阶段，尿道周围骨骼肌EMG活动记录中出现振荡性爆发活动；在膀胱内压上升最快时尤其如此，且持续80 - 270毫秒的电静息期与尿道周围EMG的活动爆发交替出现。（4）在本实验中，由与膀胱内压相关的盆神经传入信号激活的转换机制逆转了许多反射通路的行为。当膀胱压力较低时，对会阴皮肤进行伤害性夹捏通常会导致膀胱收缩以及盆神经传出活动和尿道周围EMG活动增加。当膀胱充盈时，存在排尿收缩，此时对会阴皮肤夹捏会使其大小和频率降低。盆神经传出活动相应减少，而在伤害性刺激期间及之后，EMG活动增加。用冰敷阴囊皮肤也会降低膀胱收缩频率。（5）当膀胱压力较低时，肛门和结肠扩张会增加尿道周围EMG活动，但不影响膀胱张力。然而，当膀胱充盈时，这些刺激会降低膀胱收缩的大小和频率，同时盆神经传出活动减少。尿道周围肌肉的EMG活动通常也会同时降低。在精囊或阴道扩张期间或向输精管腔内注射20 - 60微升盐水后，也获得了类似结果。在每种情况下，都观察到了膀胱内压极端情况下反应的逆转。（6）在颈上段或胸段进行脊髓横断后，在膀胱高容量时不存在排尿收缩。然而，当神经轴完整且膀胱压力较低时所描述的效应仍然可以观察到。（摘要截断于400字）
