Farncombe Family Digestive Health Research Institute, McMaster University, Hamilton, ON, Canada; Department of Pathology and Molecular Medicine, McMaster University, Hamilton, ON, Canada.
Department of Immunology and Internal Medicine, University of Manitoba, Winnipeg, Manitoba, Canada.
Biochimie. 2019 Jun;161:56-64. doi: 10.1016/j.biochi.2018.06.008. Epub 2018 Jun 14.
Serotonin (5-hydroxytryptamine or 5-HT) once most extensively studied as a neurotransmitter of the central nervous system, is seen to be predominantly secreted in the gut. About 95% of 5-HT is estimated to be found in gut mainly within the enterochromaffin cells whereas about 5% is found in the brain. 5-HT is an important enteric signaling molecule and is well known for playing a key role in sensory-motor and secretory functions in the gut. In recent times, studies uncovering various new functions of gut-derived 5-HT indicate that many more are yet to be discovered in coming days. Recent studies revealed that 5-HT plays a pivotal role in immune cell activation and generation/perpetuation of inflammation in the gut. In addition to its various roles in the gut, there are now emerging evidences that suggest an important role of gut-derived 5-HT in other biological processes beyond the gut, such as bone remodeling and metabolic homeostasis. This review focuses to briefly summarize the accumulated and newly updated role of 5-HT in the maintenance of normal gut physiology and in the pathogenesis of inflammation in the gut. The collected information about this multifaceted signaling molecule may aid in distinguishing its good and bad effects which may lead to the development of novel strategies to overcome the unwanted effect, such as in inflammatory bowel disease.
血清素（5-羟色胺或 5-HT）曾被广泛研究为中枢神经系统的神经递质，现在被认为主要在肠道中分泌。据估计，约 95%的 5-HT 存在于肠道中，主要存在于肠嗜铬细胞内，而约 5%存在于大脑中。5-HT 是一种重要的肠内信号分子，它在肠道的感觉-运动和分泌功能中起着关键作用。最近的研究揭示了肠道来源的 5-HT 的各种新功能，表明在未来的日子里，还有更多的功能有待发现。最近的研究表明，5-HT 在免疫细胞的激活和肠道炎症的产生/持续中起着关键作用。除了在肠道中的各种作用外，现在有越来越多的证据表明，肠道来源的 5-HT 在肠道以外的其他生物学过程中也起着重要作用，如骨骼重塑和代谢稳态。这篇综述旨在简要总结 5-HT 在维持正常肠道生理学和肠道炎症发病机制中的积累和最新作用。关于这种多方面信号分子的信息可能有助于区分其好坏影响，这可能导致开发克服不良影响的新策略，如在炎症性肠病中。
