Dopamine in the Gut | 2021
Synthesis and Metabolism of Gut Dopamine
Abstract
Not only the central nervous system can produce dopamine (DA), the gastrointestinal tract is also an important source of DA, such as gastric mucosa and pancreas. Additionally, colonic lumen also contains substantial DA. The rapid degradation of DA ensures its proper function in various locations in the body. Monoamine oxidase (MAO) and catechol-O-methyltransferase (COMT) are the main metabolic enzymes of DA and are widely distributed in the gut. The altered contents or activities of these enzymes could cause the changes of DA levels in the gut, thereby might be correlated to some gastrointestinal disorders. Although the function and degradation of luminal DA are still unknown, a number of studies have reported that gut microbiota is involved in the progress of many diseases, such as Parkinson’s disease, irritable bowel syndrome (IBS), and inflammatory bowel disease (IBD). Besides, the relationship between luminal DA and gut microbiome has been reported. In the present chapter, we focus on the sources and metabolism of gut DA, the distribution and function of MAO and COMT in various regions of gut, as well as the relationship among gut microbiome, luminal DA, and gastrointestinal disorders.