In ORS, the effect of glucose on sodium absorption is: September 2005
**Core Concept**
The oral rehydration solution (ORS) is a balanced mixture of water, salts, and sugars that helps replace lost fluids and electrolytes in the body. The addition of glucose to ORS enhances sodium absorption in the small intestine through a co-transport mechanism.
**Why the Correct Answer is Right**
Glucose stimulates the sodium-glucose co-transporter (SGLT1) in the intestinal epithelial cells, which increases the absorption of sodium ions from the lumen into the cells. This process is essential for maintaining proper fluid balance and preventing dehydration. The sodium ions are then transported to the bloodstream, where they help regulate the balance of fluids within the body.
**Why Each Wrong Option is Incorrect**
**Option A:** Glucose has no effect on sodium absorption in ORS. This is incorrect because glucose plays a crucial role in enhancing sodium absorption through the SGLT1 co-transport mechanism.
**Option B:** Glucose inhibits sodium absorption in ORS. This is incorrect because glucose stimulates sodium absorption, not inhibits it.
**Option C:** The effect of glucose on sodium absorption in ORS is not well understood. This is incorrect because the mechanism of glucose-stimulated sodium absorption has been well established through research and is a fundamental principle of ORS composition.
**Clinical Pearl / High-Yield Fact**
A key aspect of ORS formulation is the optimal balance between glucose and sodium, as excessive glucose can lead to osmotic diarrhea, while inadequate glucose can impair sodium absorption.
**Correct Answer: B. Glucose increases sodium absorption in ORS.**