Question

Which metabolite is used to inactivate the vasico-toxic metabolite leading to hemorrhagic cystitis by alkylating agent used in the treatment of cancer

• A. Acrolein
• B. Aldophosphamide
• C. Cyclophosphamide
• D. Mesna

Answer 1

The Correct Option is B

To solve this question, it is essential first to understand the context and the properties of the compounds listed in the options. The question is about a metabolite that inactivates a vasico-toxic compound responsible for causing hemorrhagic cystitis, a side effect associated with certain alkylating agents used in cancer treatment.

Let's analyze each option: 

1. Acrolein: Acrolein is a toxic metabolite that is actually responsible for causing hemorrhagic cystitis when alkylating agents like cyclophosphamide are used. Thus, it does not inactivate the vasico-toxic metabolite; it is the toxic metabolite.
2. Aldophosphamide: Aldophosphamide is an intermediate in the metabolism of cyclophosphamide. It doesn't act to inactivate the toxic metabolites; instead, it is part of the process that leads to their formation.
3. Cyclophosphamide: This is the parent alkylating agent whose use leads to the production of acrolein and other metabolites. It is indeed integral to the pathway but not the inactivator of the toxic metabolites.
4. Mesna (sodium 2-mercaptoethanesulfonate): This compound is used prophylactically with alkylating agents to inactivate acrolein. It binds to acrolein in the urinary tract, thereby preventing it from causing harm to the bladder lining.

Therefore, based on the above reasoning, the correct answer should be Mesna, even though the originally provided answer was

Aldophosphamide

. Mesna is widely documented and used clinically to prevent hemorrhagic cystitis caused by the toxic metabolite acrolein during chemotherapy.