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

ORS and intestinal glucose transport:

The scientific basis of ORS is the glucose-sodium co-transport system in the gut, discovered in the 1960s. Even during active secretory diarrhea, the absorptive mechanism of the enterocyte remains intact.

Glucose transporters comparison:

• SGLT-1: Apical membrane of small intestinal enterocytes; co-transports 1 glucose + 2 Na+ (secondary active); the key transporter for ORS absorption -- CORRECT
• SGLT-2: Kidney proximal tubule (S1 segment); reabsorbs ~90% of filtered glucose; target of gliflozin drugs; NOT in intestine
• GLUT-2: Basolateral membrane of enterocytes; exports glucose from enterocyte into blood (facilitative, not sodium-linked)
• GLP-1: An incretin hormone from intestinal L-cells -- not a transporter at all
• GLUT-1: RBCs, blood-brain barrier -- not relevant to intestinal ORS absorption

The sodium gradient driving SGLT-1 is maintained by the basolateral $Na^+/K^+$-ATPase, making this an example of secondary active transport.
\[\boxed{\text{SGLT-1}}\]