Hellström P M, Sjöqvist A
Department of Internal Medicine, Karolinska Hospital, Stockholm, Sweden.
Acta Physiol Scand. 1988 Aug;133(4):559-62. doi: 10.1111/j.1748-1716.1988.tb08441.x.
The present study was performed to investigate mechanisms involved in urinary bladder relaxation during reflex activation of the pelvic nerves in the cat. Electrical stimulation of the pelvic nerves produced a contraction of the urinary bladder (P less than 0.05) and colon (P less than 0.05). Reflex activation of the pelvic nerves by rectal distension or mechanical stimulation of the anus induced relaxation of the bladder (P less than 0.05), while a colonic contraction was elicited (P less than 0.05). Naloxone (1.5 mg kg-1, i.v.) abolished the reflex inhibition of bladder motility elicited by rectal distension or mechanical stimulation of the anus (P less than 0.05). However, the urinary bladder and colonic contraction produced by electrical stimulation of the pelvic nerves were not affected. Hexamethonium (10 mg kg-1, i.v.) or severing of the pelvic nerves completely abolished the responses of the urinary bladder and colon to electrical stimulation or reflex activation of the pelvic nerves. The results indicate that inhibitory reflexes from the rectum and anal canal to the urinary bladder are conveyed via efferents of the pelvic nerves, and involve both nicotinic and opioid receptor mechanisms.
本研究旨在探讨猫盆腔神经反射激活期间膀胱舒张所涉及的机制。电刺激盆腔神经可使膀胱（P<0.05）和结肠（P<0.05）收缩。直肠扩张或肛门机械刺激引起的盆腔神经反射激活可诱导膀胱舒张（P<0.05），同时引发结肠收缩（P<0.05）。纳洛酮（1.5mg/kg，静脉注射）可消除直肠扩张或肛门机械刺激引起的膀胱运动反射抑制（P<0.05）。然而，电刺激盆腔神经所产生的膀胱和结肠收缩不受影响。六甲铵（10mg/kg，静脉注射）或切断盆腔神经可完全消除膀胱和结肠对电刺激或盆腔神经反射激活的反应。结果表明，从直肠和肛管到膀胱的抑制性反射通过盆腔神经传出纤维传导，且涉及烟碱样和阿片受体机制。
