EFFECT OF CAPSAICIN ON MICTURITION AND ASSOCIATED REFLEXES IN CHRONIC SPINAL RATS
EFFECT OF CAPSAICIN ON MICTURITION AND ASSOCIATED REFLEXES IN CHRONIC SPINAL RATS
复制标题
DOI：
10.1016/0006-8993(95)00212-9
复制
发表时间：
1995-04-24
期刊：
影响因子：
2.9
通讯作者：
DEGROAT, WC
中科院分区：
文献类型：
--
作者：
CHENG, CL;MA, CP;DEGROAT, WC
我们研究了辣椒素敏感的膀胱传入神经在非麻醉慢性脊髓大鼠排尿中的作用。脊髓损伤(SCI)后5~9d出现触觉刺激所致的反射性排尿，2~3周出现膀胱扩张所致的排尿。在等容条件下记录的反射性膀胱收缩的频率和幅度在慢性脊髓和乌拉坦麻醉的中枢神经系统完整大鼠中相似。然而，脊髓损伤后6-8周进行的膀胱测量(CMG)显示，慢性脊髓损伤大鼠的膀胱容量(1.86毫升)大于中枢神经系统正常大鼠(0.48毫升)，并且还表现出中枢神经系统正常大鼠所未检测到的多次、小幅度、无排尿的膀胱收缩。辣椒素(50 mg/kg皮下注射)急性(起病14-40分钟)抑制慢性脊髓动物膀胱扩张或刺激引起的反射性膀胱活动。而慢性脊髓损伤大鼠在实验前4天皮下注射辣椒素(125 mg/kg)，并不抑制排尿反射或改变膀胱容量，但可消除非排尿收缩。机械刺激直肠肛管或宫颈阴道对反射性膀胱收缩的抑制不受辣椒素的影响。这些数据表明，辣椒素敏感的膀胱传入在慢性脊髓大鼠反射排尿的启动中不是必需的。然而，在CMG的充盈阶段，这些传入确实会导致膀胱的过度活动。因此，辣椒素敏感的膀胱传入应该被评估为SCI患者膀胱反射亢进的药物治疗的可能靶点。
The role of capsaicin-sensitive bladder afferents in micturition was studied in unanesthetized chronic spinal rats. Reflex voiding in response to tactile stimulation of the perigenital region appeared 5-9 days after spinal cord injury (SCI) whereas voiding induced by bladder distension occurred 2-3 weeks after SCI. The frequency and amplitude of reflex bladder contractions recorded under isovolumetric conditions were similar in chronic spinal and urethane-anesthetized CNS-intact rats. However, cystometrograms (CMGs) performed 6-8 weeks after SCI revealed that the chronic spinal rats had larger bladder capacities (1.86 mi) than CNS-intact rats (0.48 ml) and also exhibited multiple, small-amplitude, nonvoiding bladder contractions that were not detected in CNS-intact rats. Administration of capsaicin (50 mg/kg s.c.) acutely (onset 14-40 min) suppressed reflex bladder activity induced by bladder distension or by perigenital stimulation in chronic spinal animals. However, pretreatment of chronic spinal rats with capsaicin (125 mg/kg s.c.) 4 days before the experiment, did not depress voiding reflexes or change bladder capacity but did eliminate the nonvoiding contractions. Inhibition of reflex bladder contractions by mechanical stimulation of rectoanal canal or the uterine cervix-vagina was not altered by pretreatment with capsaicin. These data indicate that capsaicin-sensitive bladder afferents are not essential for the initiation of reflex micturition in chronic spinal rats. However, these afferents do contribute to hyperactivity of the bladder during the filling phase of the CMG. Thus, capsaicin-sensitive bladder afferents should be evaluated as possible targets for the pharmacological treatment of bladder hyperreflexia in patients with SCI.