Question

Receptor for absorption of glucose in intestine when a person is given ORS is:

• A. SGLT-1
• B. SGLT-2
• C. GLP-1
• D. GLUT-1

Hint:

ORS efficacy depends on sodium-glucose co-transport at the apical surface of small intestinal enterocytes.

Answer 1

The Correct Option is A

Step 1: Understand ORS mechanism. Oral Rehydration Solution (ORS) contains glucose and sodium in a specific ratio. The rationale is that glucose and sodium are co-transported together, driving water absorption even in the presence of secretory diarrhea (e.g., cholera).

Step 2: Identify the transporter. SGLT-1 (Sodium-Glucose Linked Transporter 1) is located on the apical (luminal) membrane of enterocytes in the small intestine. It co-transports 1 glucose molecule with 2 sodium ions (secondary active transport, driven by the sodium gradient maintained by the basolateral Na+/K+-ATPase). This is the principal transporter responsible for intestinal glucose absorption.

Step 3: Distinguish from other transporters.

• SGLT-2: Located in the proximal tubule of the kidney (not intestine); responsible for renal glucose reabsorption; target of SGLT-2 inhibitor drugs (gliflozins).
• GLP-1: Glucagon-like peptide 1 -- a hormone secreted by L-cells of the intestine in response to food; it is not a glucose transporter.
• GLUT-1: A facilitative glucose transporter (not sodium-coupled); present in erythrocytes and blood-brain barrier; not primarily responsible for intestinal glucose absorption from ORS.

Conclusion: The transporter responsible for intestinal glucose absorption (and the basis for ORS efficacy) is SGLT-1.