From the Research
The sodium-dependent glucose transporter at the basolateral surface of intestinal and renal epithelial cells is GLUT2 (Glucose Transporter 2). This transporter is responsible for the facilitated diffusion of glucose, galactose, and fructose across the basolateral membrane into the bloodstream after these sugars have been actively transported into the epithelial cells by SGLT1 at the apical membrane 1. The mechanism of GLUT2 is distinct from SGLT1, which is a sodium-glucose cotransporter that uses the sodium gradient for active transport, whereas GLUT2 functions as a passive transporter that allows sugars to move down their concentration gradient without requiring energy 2. Key characteristics of GLUT2 include its relatively low affinity but high capacity for glucose transport, making it ideal for handling the high concentrations of glucose that accumulate inside epithelial cells after active transport by SGLT1 1. Some of the key points about GLUT2 and its role in glucose transport include:
- GLUT2 is localized in the basolateral membrane (BLM) of enterocytes and is involved in the absorption of D-glucose and D-galactose 1
- GLUT2 has a high capacity for glucose transport, which is essential for handling the high concentrations of glucose that accumulate inside epithelial cells after active transport by SGLT1 1
- The expression of GLUT2 is closely correlated with that of SGLT2, and both are slightly lower in people with type 2 diabetes compared to those without diabetes 3
- GLUT2 plays a crucial role in the reabsorption of filtered glucose in the kidney tubules and the absorption of dietary carbohydrates in the small intestine 1, 2