intestinal D-glucose absorption

Definition

Target type: biologicalprocess

Uptake of D-glucose into the blood by absorption from the small intestine. [GOC:mgi_curators, PMID:5601832]

The absorption of D-glucose in the intestine is a complex process involving several steps and key players. First, dietary carbohydrates are broken down into monosaccharides, primarily glucose, by the action of enzymes in the mouth and small intestine. Once glucose reaches the small intestine, it is transported across the intestinal epithelium, the lining of the small intestine, and into the bloodstream. This process involves two main mechanisms:

1. **Passive Diffusion:** This mechanism occurs when glucose concentration is higher in the lumen of the small intestine compared to the epithelial cells. Glucose diffuses passively across the intestinal epithelial cells following its concentration gradient.

2. **Active Transport:** This mechanism involves the use of energy to transport glucose against its concentration gradient, from the lumen of the small intestine to the epithelial cells. Active transport is facilitated by the Sodium-Glucose Cotransporter 1 (SGLT1), a protein located on the apical membrane of the intestinal epithelial cells. SGLT1 uses the electrochemical gradient of sodium (Na+) to move glucose against its concentration gradient into the epithelial cells. The sodium ions are then pumped out of the epithelial cells by the sodium-potassium pump (Na+/K+ ATPase), using ATP as an energy source.

Once inside the epithelial cells, glucose is transported across the basolateral membrane, the side facing the blood vessels, by glucose transporters (GLUT2). GLUT2 is a passive transporter that facilitates the movement of glucose down its concentration gradient into the blood.

The absorbed glucose is then transported to the liver via the hepatic portal vein, where it can be used for energy production, stored as glycogen, or converted into other molecules.

The absorption of glucose is a highly regulated process that is influenced by several factors, including dietary intake, hormonal signals, and the presence of other nutrients. This intricate process ensures that the body receives adequate glucose for its energy needs while maintaining appropriate blood glucose levels.'
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Proteins (2)

Compounds (16)