Faculty of Nursing and Occupational Therapy, Department of Physiology, University of Extremadura, Caceres, Spain.
Am J Physiol Gastrointest Liver Physiol. 2014 Apr 1;306(7):G614-21. doi: 10.1152/ajpgi.00208.2013. Epub 2014 Feb 13.
The main roles of the colonic mucosa are the absorption of water and electrolytes and the barrier function that preserves the integrity of the colonic wall. The mediators and mechanisms to accomplish these functions are under continuous investigation, but little attention has been paid to a possible control of colonic motility by the mucosa that would fine tune the relationship between absorption and motility. The purpose of this study was to establish the role of the mucosa in the control of induced colonic contractility. Young ICR-CD1 mice (3-5 mo old) were studied. Isometric tension transducers were used to record contractility in full-thickness (FT) and mucosa-free (MF) strips from proximal colon. Proximal FT strips showed lower KCl- and bethanechol-induced responses than MF strips. The difference was not due to mechanical artefacts since the contractile response of FT strips to electrical field stimulation was around 50% lower than in MF. The inhibitory effects of the mucosa on FT strips were mimicked by immersion of separate strips of mucosa in the organ bath but not by addition of mucosal extract, suggesting gaseous molecules as mediators of this effect. Incubation of MF strips with synthase inhibitors of nitric oxide, carbon monoxide, and hydrogen sulfide abolished the inhibition caused by addition of the mucosal strip, indicating that mucosal gasotransmitters are the mediators of these effects. This suggests that the control of colonic motility exerted by the mucosa could fine tune the balance between transit and absorption.
结肠黏膜的主要作用是吸收水分和电解质以及维持结肠壁完整性的屏障功能。完成这些功能的介质和机制仍在不断研究中，但很少有人关注黏膜对结肠蠕动的可能控制，以精细调节吸收和蠕动之间的关系。本研究旨在确定黏膜在控制诱导性结肠收缩性中的作用。研究了年轻的 ICR-CD1 小鼠（3-5 月龄）。使用等长张力换能器记录来自近端结肠的全层（FT）和无黏膜（MF）条带的收缩性。与 MF 条带相比，近端 FT 条带的 KCl 和氨甲酰胆碱诱导的反应较低。这种差异不是由于机械伪影引起的，因为 FT 条带对电场刺激的收缩反应比 MF 低约 50%。将单独的黏膜条带浸入器官浴中可以模拟黏膜对 FT 条带的抑制作用，但添加黏膜提取物则不能，这表明气态分子是这种作用的介导物。用一氧化氮、一氧化碳和硫化氢合酶抑制剂孵育 MF 条带可以消除添加黏膜条带引起的抑制，表明黏膜气体递质是这些作用的介导物。这表明，黏膜对结肠蠕动的控制可以精细调节转运和吸收之间的平衡。
