钙通道和细胞内钙信号对小肠葡萄糖吸收的调节作用及机制

Mechanisms of Ca^(2+) channels and the intracellular calcium signal in the regulating of glucose uptake in small intestine

迄今为止葡萄糖在小肠黏膜的吸收机制已被系统地阐明和接受,即经典的钠葡萄糖同向转运体(SGLT1)介导的主动转运机制。此外,当肠腔葡萄糖浓度高于SGLT1的转运饱和度时,葡萄糖转运蛋白2(GluT2)可能一过性易位于小肠黏膜上皮细胞顶膜来参与葡萄糖的异化扩散吸收,但小肠黏膜上皮细胞葡萄糖吸收的调节机制仍然不是完全清楚。近年来钙离子通道(CRAC)及细胞内钙信号对葡萄糖的吸收调节作用备受关注,二者可通过调节肠道葡萄糖转运体SGLT1和GluT2的表达及功能来调节小肠葡萄糖的吸收。本文以CRAC及细胞内钙信号对小肠黏膜上皮细胞葡萄糖的吸收调节作用及其分子机制进行论述,希望能为肥胖及其相关疾病的防治提供新的视野及潜在的新药研发靶点。

To date the classical pathway of glucose absorption from intestinal lumen into enterocytes by the Na＋/glucose cotransporter （SGLT1）tins been systemically studied in details and universally accepted. However, when the glucose concentration in the intestine is beyond the transport saturation of SGLTl,glucose transporter type 2 （GIuT2） may also play a role by transient translocation of GluT2 from cytoplasmic vesicles into the apical membrane to absorb glucose by the facilitated diffusion, while the regulatory mechanism of glucose absorption still remains unclear. It has recently attracted much interest in which the calcium channels and the intracellular calcium signal can regulate the absorption of glucose by adjusting the expression and function of GluT2 and SGLT1. In this review, we retrospect the involvements of Ca2＋ channels and the intracellular Calcium signal in the regulation and the molecular mechanism of glucose uptake in small intestine and hope to provide the novel fields and new drug research targets for the prophylaxis and treatment of obesity and the related diseases.