Question

Given below are two statements, one is labelled as Assertion (A) and other one labelled as Reason (R).
Assertion (A) : Oxalate poisoning in animals occurs after ingestion of large quantities of plants containing oxalates.
Reason (R) : Poisoning occurs due to interaction of oxalates with calcium in the gut.
In light of above statements, choose the correct answer from the options given below:

• A. Both (A) and (R) are true and (R) is the correct explanation of (A).
• B. Both (A) and (R) are true but (R) is NOT the correct explanation of (A).
• C. (A) is true but (R) is false.
• D. (A) is false but (R) is true.

Hint:

Calcium-oxalate binding in the gut is a protective mechanism. Systemic oxalate poisoning occurs because of absorbed oxalates binding systemic calcium in the blood, causing hypocalcemia and renal failure.

Answer 1

The Correct Option is C

Step 1: Understanding the Concept:
Oxalate poisoning occurs in grazing animals (especially sheep and cattle) after ingesting plants containing high concentrations of soluble oxalates (such as soursob or setaria grass).
Detailed Explanation:
Let us analyze the statements:
- Assertion (A) analysis: Ingesting large quantities of oxalate-rich plants leads to clinical poisoning in grazing animals. Thus, Assertion (A) is true.
- Reason (R) analysis: Soluble oxalates (such as sodium and potassium oxalates) react with calcium inside the digestive tract (rumen/gut) to form insoluble calcium oxalate, which is excreted in the feces. However, this gut interaction actually protects the animal by rendering the oxalate non-absorbable. The actual systemic poisoning (toxicity) occurs because any absorbed soluble oxalates bind to systemic calcium in the bloodstream, causing acute hypocalcemia (low blood calcium levels) and precipitating as crystals in the renal tubules, leading to kidney damage. Thus, the statement that the poisoning is caused by the interaction of oxalates with calcium in the *gut* is scientifically false.

Step 2: Final Answer:
Since Assertion (A) is true and Reason (R) is false, the correct choice is Option (C).