PDF(Pubmed)
Abstract：
The oral detection of sugars relies on two types of receptor systems. The first is the G-protein-coupled receptor TAS1R2/TAS1R3. When activated, this receptor triggers a downstream signaling cascade involving gustducin, phospholipase Cβ2 (PLCβ2), and transient receptor potential channel M5 (TRPM5). The second type of receptor is the glucose transporter. When glucose enters the cell via this transporter, it is metabolized to produce ATP. This ATP inhibits the opening of KATP channels, leading to cell depolarization. Beside these receptor systems, sweet-sensitive taste cells have mechanisms to regulate their sensitivity to sweet substances based on internal and external states of the body. Sweet taste receptors are not limited to the oral cavity; they are also present in extraoral organs such as the gastrointestinal tract, pancreas, and brain. These extraoral sweet receptors are involved in various functions, including glucose absorption, insulin release, sugar preference, and food intake, contributing to the maintenance of energy homeostasis. Additionally, sweet receptors may have unique roles in certain organs like the trachea and bone. This review summarizes past and recent studies on sweet receptor systems, exploring the molecular mechanisms and physiological functions of sweet (sugar) detection in both oral and extraoral organs.
摘要：
糖的口服检测依赖于两种类型的受体系统。第一个是G蛋白偶联受体TAS1R2/TAS1R3。激活时,这个受体触发了一个下游的信号级联反应，磷脂酶Cβ2（PLCβ2），和瞬时受体电位通道M5(TRPM5)。第二种类型的受体是葡萄糖转运蛋白。当葡萄糖通过这种转运蛋白进入细胞时，代谢产生ATP。这种ATP抑制KATP通道的开放，导致细胞去极化。除了这些受体系统，对甜味敏感的味觉细胞具有基于身体内部和外部状态调节其对甜味物质的敏感性的机制。甜味受体不限于口腔;它们也存在于口腔外器官，如胃肠道，胰腺,和大脑。这些口外甜味受体参与各种功能，包括葡萄糖吸收，胰岛素释放，糖偏好，和食物摄入，有助于维持能量稳态。此外,甜味受体可能在某些器官如气管和骨骼中具有独特的作用。这篇综述总结了过去和最近对甜味受体系统的研究，探索口腔和口外器官中甜味（糖）检测的分子机制和生理功能。
