Tan Wei, Lee Grace, Chen Ji-Hong, Huizinga Jan D
Department of Gastroenterology, Renmin Hospital of Wuhan University, Wuhan, China.
Department of Medicine, Division of Gastroenterology, Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada.
Front Physiol. 2020 Feb 18;11:109. doi: 10.3389/fphys.2020.00109. eCollection 2020.
BACKGROUND/AIMS: Luminal factors such as short-chain fatty acids are increasingly recognized for playing a regulatory role in peristaltic activity. Our objective was to understand the roles of butyrate and propionate in regulating peristaltic activity in relation to distention-induced activities.
Butyrate and propionate were perfused intraluminally under varying intraluminal pressures in murine colons bathed in Krebs solution. We used video recording and spatiotemporal maps to examine peristalsis induced by the intrinsic rhythmic colonic motor complex (CMC) as well as pellet-induced peristaltic reflex movements.
The CMC showed several configurations at different levels of excitation, culminating in long distance contractions (LDCs) which possess a triangular shape in murine colon spatiotemporal maps. Butyrate increased the frequency of CMCs but was a much weaker stimulus than distention and only contributed to significant changes under low distention. Propionate inhibited CMCs by decreasing either their amplitudes or frequencies, but only in low distention conditions. Butyrate did not consistently counteract propionate-induced inhibition likely due to the multiple and distinct mechanisms of action for these signaling molecules in the lumen. Pellet movement occurred through ongoing CMCs as well as pellet induced peristaltic reflex movements and butyrate augmented both types of peristaltic motor patterns to decrease the amount of time required to expel each pellet.
Butyrate is effective in promoting peristalsis, but only when the level of colonic activity is low such as under conditions of low intraluminal pressure. This suggests that it may play a significant role in patients with poor fiber intake, where there is low mechanical stimulation in the lumen.
背景/目的：短链脂肪酸等肠腔因素在蠕动活动中的调节作用日益受到认可。我们的目的是了解丁酸盐和丙酸盐在调节与扩张诱导活动相关的蠕动活动中的作用。
在 Krebs 溶液中浸泡的小鼠结肠内，在不同的腔内压力下腔内灌注丁酸盐和丙酸盐。我们使用视频记录和时空图来检查由内在节律性结肠运动复合体（CMC）诱导的蠕动以及粪便诱导的蠕动反射运动。
CMC 在不同的兴奋水平下呈现出几种形态，最终形成长距离收缩（LDCs），在小鼠结肠时空图中呈三角形。丁酸盐增加了 CMC 的频率，但比扩张刺激弱得多，仅在低扩张情况下导致显著变化。丙酸盐通过降低 CMC 的幅度或频率来抑制 CMC，但仅在低扩张条件下。丁酸盐可能由于这些信号分子在肠腔内的多种不同作用机制，并未始终抵消丙酸盐诱导的抑制作用。粪便运动通过持续的 CMC 以及粪便诱导的蠕动反射运动发生，丁酸盐增强了这两种蠕动运动模式，以减少排出每个粪便所需的时间。
丁酸盐在促进蠕动方面有效，但仅在结肠活动水平较低时，如腔内压力较低的情况下。这表明它可能在纤维摄入量低、肠腔内机械刺激少的患者中发挥重要作用。
