5-HT7受体激动剂改善脊髓损伤大鼠排尿障碍

目的:研究五羟色胺-7受体激动剂对慢性脊髓损伤(spinal cord injury,SCI)大鼠排尿障碍的改善作用。方法:体重175～200g之间的SD雌性大鼠,脊髓损伤模型7只,正常对照8只。乌拉坦麻醉下,在正常大鼠和脊髓损伤的模型的大鼠颈静脉和膀胱内置管,连接压力感受器,记录膀胱最大容量、剩余尿量、排尿量和尿道外括约肌的肌电活动。静脉注入5-HT7受体激动剂LP44(3～300μg/kg)得到剂量-效应曲线随后再给予5-HT7受体抑制剂SB269970(100μg/kg)。结果:LP44剂量依赖性的降低SCI大鼠膀胱最大容量,并且增加排尿量、减少剩余尿量从而增加排尿效率。但是不能引起脊髓完好的大鼠排尿的改变。SB269970注入后可以逆转LP44的作用。同时LP44引起脊髓损伤大鼠尿道外括约肌强直收缩中出现阶段性的松弛,而对于脊髓完好的大鼠作用无明显改变。结论:LP44可以剂量依赖性地部分恢复SCI大鼠的尿道外括约肌协调性松弛,从而降低膀胱容量,增加排尿量,减少剩余尿量,结果增加排尿效率,改善排尿障碍。

Improving the voding disfunction by a 5-HT7 receptor agonist in rats with chronic spinal cord injury

Objective:To investigate the effect of 5-hydroxytryptamine serotonin 7receptor agonists on micturition dysfunction in rats with chronic spinal cord injury(SCI).Method:Intact rats and SCI rats were catheterized through the bladder dome for saline-filling cystometry.Dose-response curves for i.v.LP44were followed each by SB269970.The capacity,residual volume,micturition volume,and voiding pressure were measured.Result:Intact rats showed few significant changes in cystometric variable.SCI rats responded to LP44with dose-dependent increase in micturition volume and decrease in capacity,residual volume and voiding pressure,resulting in improvement in voiding efficiency.Effects of LP44were reversed by SB269970.Conclusion:LP44is of some help to improvement in voiding efficiency through induced emergence of phasic EUS relaxation.