de Groat W C
Department of Pharmacology, University of Pittsburgh, PA 15261.
Ciba Found Symp. 1990;151:27-44; discussion 44-56. doi: 10.1002/9780470513941.ch3.
The lower urinary tract has two main functions, the storage and periodic elimination of urine, which are regulated by a complex neural control system in the brain and spinal cord. This neural system exhibits switch-like patterns of activity that are generated by visceral reflex circuits, some of which are under voluntary control. Experimental studies in animals indicate that the micturition reflex is mediated by a spinobulbospinal pathway passing through a coordination centre (the pontine micturition centre) located in the rostral brainstem. This reflex pathway is, in turn, modulated by higher centres in the cerebral cortex which are presumably involved in the voluntary control of micturition. Several neurotransmitters (including GABA, opioid peptides and glutamic acid) appear to have a role in the central pathways controlling micturition. Since pharmacological manipulation of putative inhibitory transmitter mechanisms increases bladder activity and decreases bladder capacity it is possible that similar changes induced by pathological conditions may underlie bladder dysfunctions occurring in patients with neurogenic urinary incontinence. Further study of these neurotransmitter systems may yield new therapeutic approaches for the treatment of hyperactive bladder disorders.
下尿路有两个主要功能，即尿液的储存和定期排出，这由大脑和脊髓中的复杂神经控制系统调节。该神经系统表现出由内脏反射回路产生的类似开关的活动模式，其中一些受自主控制。动物实验研究表明，排尿反射由一条经位于脑桥上部脑干的协调中心（脑桥排尿中枢）的脊髓-延髓-脊髓通路介导。反过来，这条反射通路又受到大脑皮层高级中枢的调节，这些高级中枢可能参与排尿的自主控制。几种神经递质（包括γ-氨基丁酸、阿片肽和谷氨酸）似乎在控制排尿的中枢通路中起作用。由于对假定的抑制性递质机制进行药理学操作会增加膀胱活动并降低膀胱容量，因此病理状况引起的类似变化可能是神经源性尿失禁患者膀胱功能障碍的基础。对这些神经递质系统的进一步研究可能会产生治疗膀胱过度活动症的新方法。
