Wrathall Jean R, Emch Gregory S
Department of Neuroscience, Georgetown University Medical Center, TRB EP04, Washington, DC 20057, USA.
Prog Brain Res. 2006;152:117-34. doi: 10.1016/S0079-6123(05)52008-9.
Lower urinary tract dysfunction is a serious burden for patients following spinal cord injury. Patients are usually limited to treatment with urinary drainage catheters, which can lead to repeated urinary tract infections and lower quality of life. Most of the information previously obtained regarding lower urinary tract function after spinal cord injury has been in completely transected animals. After thoracic transection in the rat, plasticity of local lumbosacral spinal circuitry establishes a "reflex bladder," which results in partial recovery of micturition, albeit with reduced voiding efficiency. Since at least half of cord-injured patients exhibit neurologically incomplete injury, rat models of clinically relevant incomplete contusion injury have been developed. With respect to lower urinary tract function, recent anatomical and physiological studies have been performed after incomplete thoracic contusion injury. The results show greater recovery of lower urinary tract function that varies inversely with the severity of the initial trauma and is positively correlated with time after injury. Recovery, as measured by coordination of the bladder with the external urethral sphincter, occurs between 1 and 4 weeks after spinal cord injury. It is associated with normalization of: serotonin immunoreactivity and glutamate receptor subunit mRNA expression in the dorsolateral nucleus that innervates the external urethral sphincter muscle, the response to glutamatergic pharmacological probes administered at the lumbosacral spinal cord level, and c-Fos activation patterns in the lumbar spinal cord. Understanding the mechanisms involved in this recovery will provide a basis for enhancing lower urinary tract function in patients after incomplete spinal cord injury.
下尿路功能障碍是脊髓损伤患者面临的严重负担。患者通常只能使用导尿管进行治疗，这可能导致反复的尿路感染并降低生活质量。先前获得的关于脊髓损伤后下尿路功能的大多数信息都来自动物完全横断模型。大鼠胸段横断后，腰骶部脊髓局部回路的可塑性建立了一个“反射膀胱”，这使得排尿功能部分恢复，尽管排尿效率有所降低。由于至少一半的脊髓损伤患者表现为神经学上的不完全损伤，因此已经建立了与临床相关的不完全挫伤损伤大鼠模型。关于下尿路功能，最近在不完全胸段挫伤损伤后进行了解剖学和生理学研究。结果表明，下尿路功能恢复程度更高，与初始创伤的严重程度呈负相关，与损伤后的时间呈正相关。通过膀胱与尿道外括约肌的协调性来衡量，恢复发生在脊髓损伤后的1至4周之间。它与以下方面的正常化有关：支配尿道外括约肌的背外侧核中5-羟色胺免疫反应性和谷氨酸受体亚基mRNA表达、腰骶部脊髓水平给予谷氨酸能药理学探针后的反应以及腰段脊髓中的c-Fos激活模式。了解这种恢复所涉及的机制将为改善不完全性脊髓损伤患者的下尿路功能提供基础。
