Roles of glutamatergic and serotonergic mechanisms in reflex control of the external urethral sphincter in urethane-anesthetized female rats

被引:49
作者
Chang, Hui-Yi
Cheng, Chen-Li
Chen, Jia-Jin J.
de Groat, William C.
机构
[1] Natl Cheng Kung Univ, Inst Biomed Engn, Tainan 701, Taiwan
[2] Taichung Vet Gen Hosp, Div Urol, Dept Surg, Taichung, Taiwan
[3] Univ Pittsburgh, Sch Med, Dept Pharmacol, Pittsburgh, PA USA
关键词
pelvic nerve; bladder distension; bursting activity; spinal cord injury;
D O I
10.1152/ajpregu.00780.2005
中图分类号
Q4 [生理学];
学科分类号
071003 ;
摘要
This study was conducted to examine reflex mechanisms that mediate urinary bladder and external urethral sphincter (EUS) coordination in urethane-anesthetized female Sprague-Dawley rats. We investigated the properties of EUS reflexes elicited by electrical stimulation of pelvic nerve afferent axons (pelvic-EUS reflex). The changes in the reflexes induced by bladder distension and administration of agonists or antagonists for glutamatergic or serotonergic receptors were examined. The reflexes consisted of an early response (ER, 18- to 22-ms latency) and a late, long-duration (> 100-ms latency) response (LR), which consisted of bursts of activity at 20- to 160-ms interburst intervals. In a few experiments, a reflex with an intermediate (40- to 70-ms) latency was also identified. With the bladder empty, the ER, but not the LR, was detected in the majority of experiments. The LR was markedly enhanced when the bladder was distended. The ER remained, but the LR was abolished, after spinal cord transection at T-8-T-9. The ER and LR were significantly decreased 75 and 35%, respectively, by the N-methyl-D-aspartate receptor antagonist MK-801 (0.3 mg/kg iv), but only decreased 18 and 14%, respectively, by the alpha-amino-5-methylisoxazole-4-propionate receptor antagonist LY-215490 ( 3 mg/ kg iv). The serotonin (5-HT1A) receptor agonist 8-hydroxy-2-(dinpropylamino)-tetralin ( 1 mg/ kg iv) enhanced spontaneous EUS activity and the pelvic-EUS reflex. WAY-100635 (0.1-1 mg/kg iv), a 5-HT1A antagonist, reversed the effect of 8-hydroxy-2-(di-n-propylamino)tetralin and suppressed EUS activity and the pelvic-EUS reflex. These results indicate that glutamatergic and serotonergic mechanisms are important in the reflex pathways underlying bladder-sphincter coordination in rats.
引用
收藏
页码:R224 / R234
页数:11
相关论文
共 43 条
[1]   Reflexes evoked by electrical stimulation of afferent axons in the pudendal nerve under empty and distended bladder conditions in urethane-anesthetized rats [J].
Chang, HY ;
Cheng, CL ;
Chen, JJJ ;
Peng, CW ;
de Groat, WC .
JOURNAL OF NEUROSCIENCE METHODS, 2006, 150 (01) :80-89
[2]  
CHANG HY, 2004, ABSTR SOC NEUR
[3]   Effect of capsaicin on the micturition reflex in normal and chronic spinal cord-injured cats [J].
Cheng, CL ;
Liu, JC ;
Chang, SY ;
Ma, CP ;
De Groat, WC .
AMERICAN JOURNAL OF PHYSIOLOGY-REGULATORY INTEGRATIVE AND COMPARATIVE PHYSIOLOGY, 1999, 277 (03) :R786-R794
[4]   The role of capsaicin-sensitive afferent fibers in the lower urinary tract dysfunction induced by chronic spinal cord injury in rats [J].
Cheng, CL ;
de Groat, WC .
EXPERIMENTAL NEUROLOGY, 2004, 187 (02) :445-454
[5]   Neural mechanisms of impaired micturition reflex in rats with acute partial bladder outlet obstruction [J].
Chien, CT ;
Yu, HJ ;
Lin, TB ;
Chen, CF .
NEUROSCIENCE, 2000, 96 (01) :221-230
[6]   Spinal 5-HT2 receptor-mediated facilitation of pudendal nerve reflexes in the anaesthetized cat [J].
Danuser, H ;
Thor, KB .
BRITISH JOURNAL OF PHARMACOLOGY, 1996, 118 (01) :150-154
[7]   Influence of central serotonergic mechanisms on lower urinary tract function [J].
de Groat, WC .
UROLOGY, 2002, 59 (5A) :30-36
[8]   Neural control of the urethra [J].
de Groat, WC ;
Fraser, MO ;
Yoshiyama, M ;
Smerin, S ;
Tai, C ;
Chancellor, MB ;
Yoshimura, N ;
Roppolo, JR .
SCANDINAVIAN JOURNAL OF UROLOGY AND NEPHROLOGY, 2001, 35 :35-43
[9]  
de Groat WC, 1993, AUTONOMIC NERVOUS SY
[10]   MECHANISMS UNDERLYING THE RECOVERY OF URINARY-BLADDER FUNCTION FOLLOWING SPINAL-CORD INJURY [J].
DEGROAT, WC ;
KAWATANI, M ;
HISAMITSU, T ;
CHENG, CL ;
MA, CP ;
THOR, K ;
STEERS, W ;
ROPPOLO, JR .
JOURNAL OF THE AUTONOMIC NERVOUS SYSTEM, 1990, 30 :S71-S78