Shiff S J, Soloway R D, Snape W J
J Clin Invest. 1982 Apr;69(4):985-92. doi: 10.1172/jci110538.
Previous studies showed that deoxycholic acid (DCA) stimulated migrating action potential complexes (MAPC) in the colon. The aim of this study was to clarify the mechanism of DCA-stimulated colonic motility. Myoelectrical and contractile activity were measured in New Zealand White rabbits from a loop constructed in the proximal colon. During the control period, slow waves were present at a frequency of 10.8 +/- 0.5 cycle/min and there were 1.5 +/- 0.5 MAPC/ h. After adding DCA (16 mM) to the loop the slow wave activity was unchanged. However, MAPC increased to 15.1 +/- 2.4 MAPC/h (P less than 0.001). MAPC activity was not stimulated in the colonic smooth muscle outside the loop. The intraluminal addition of procaine or tetrodotoxin to the colonic loop inhibited the DCA-stimulated increase in MAPC activity (0.2 +/- 0.2 MAPC/h) (P less than 0.005). Intravenous administration of atropine or phentolamine also inhibited MAPC activity that had been stimulated by DCA (P less than 0.005). Pretreatment with 6-hydroxydopamine also inhibited an increase in MAPC activity. Propranolol, trimethaphan camsylate, or hexamethonium had no effect on DCA stimulation of MAPC activity. Although the concentration of bile salt increased in the mesenteric venous outflow from the colonic loop, the intravenous administration of bile salt did not stimulate colonic MAPC activity. These studies suggest: (a) the action of DCA on smooth muscle activity is a local phenomenon, (b) the increase in MAPC activity is dependent on intact cholinergic and alpha adrenergic neurons, and (c) an increase in the concentration of bile salts in the serum is not associated with an increase in colonic MAPC activity.
先前的研究表明，脱氧胆酸（DCA）可刺激结肠中的移行性动作电位复合体（MAPC）。本研究的目的是阐明DCA刺激结肠运动的机制。在新西兰白兔的近端结肠构建的肠袢中测量肌电和收缩活动。在对照期，慢波频率为10.8±0.5次/分钟，每小时有1.5±0.5个MAPC。向肠袢中加入DCA（16 mM）后，慢波活动未改变。然而，MAPC增加至15.1±2.4个/小时（P<0.001）。肠袢外的结肠平滑肌中MAPC活性未受刺激。向结肠肠袢腔内加入普鲁卡因或河豚毒素可抑制DCA刺激的MAPC活性增加（0.2±0.2个/小时）（P<0.005）。静脉注射阿托品或酚妥拉明也可抑制由DCA刺激的MAPC活性（P<0.005）。用6-羟基多巴胺预处理也可抑制MAPC活性的增加。普萘洛尔、樟磺咪芬或六甲铵对DCA刺激的MAPC活性无影响。尽管结肠肠袢肠系膜静脉流出液中胆盐浓度升高，但静脉注射胆盐并未刺激结肠MAPC活性。这些研究表明：（a）DCA对平滑肌活动的作用是局部现象；（b）MAPC活性的增加依赖于完整的胆碱能和α肾上腺素能神经元；（c）血清中胆盐浓度的升高与结肠MAPC活性的增加无关。
