Research progress on the roles of dopamine and dopamine receptors in digestive system diseases.

Dopamine (DA) is a neurotransmitter synthesized in the human body that acts on multiple organs throughout the body, reaching them through the blood circulation. Neurotransmitters are special molecules that act as messengers by binding to receptors at chemical synapses between neurons. As ligands, they mainly bind to corresponding receptors on central or peripheral tissue cells. Signalling through chemical synapses is involved in regulating the activities of various body systems. Lack of DA or a decrease in DA levels in the brain can lead to serious diseases such as Parkinson's disease, schizophrenia, addiction and attention deficit disorder. It is widely recognized that DA is closely related to neurological diseases. As research on the roles of brain-gut peptides in human physiology and pathology has deepened in recent years, the regulatory role of neurotransmitters in digestive system diseases has gradually attracted researchers' attention, and research on DA has expanded to the field of digestive system diseases. This review mainly elaborates on the research progress on the roles of DA and DRs related to digestive system diseases. Starting from the biochemical and pharmacological properties of DA and DRs, it discusses the therapeutic value of DA- and DR-related drugs for digestive system diseases.