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.

Ion channels and transporters regulate nutrient absorption in health and disease.

Ion channels and transporters are ubiquitously expressed on cell membrane, which involve in a plethora of physiological process such as contraction, neurotransmission, secretion and so on. Ion channels and transporters is of great importance to maintaining membrane potential homeostasis, which is essential to absorption of nutrients in gastrointestinal tract. Most of nutrients are electrogenic and require ion channels and transporters to absorb. This review summarizes the latest research on the role of ion channels and transporters in regulating nutrient uptake such as K+ channels, Ca2+ channels and ion exchangers. Revealing the mechanism of ion channels and transporters associated with nutrient uptake will be helpful to provide new methods to diagnosis and find potential targets for diseases like diabetes, inflammatory bowel diseases, etc. Even though some of study still remain ambiguous and in early stage, we believe that ion channels and transporters will be novel therapeutic targets in the future.

Function of TRP channels in monocytes/macrophages.

The transient receptor potential channel (TRP channel) family is a kind of non- specific cation channel widely distributed in various tissues and organs of the human body, including the respiratory system, cardiovascular system, immune system, etc. It has been reported that various TRP channels are expressed in mammalian macrophages. TRP channels may be involved in various signaling pathways in the development of various systemic diseases through changes in intracellular concentrations of cations such as calcium and magnesium. These TRP channels may also intermingle with macrophage activation signals to jointly regulate the occurrence and development of diseases. Here, we summarize recent findings on the expression and function of TRP channels in macrophages and discuss their role as modulators of macrophage activation and function. As research on TRP channels in health and disease progresses, it is anticipated that positive or negative modulators of TRP channels for treating specific diseases may be promising therapeutic options for the prevention and/or treatment of disease.