Repeated USMLE Questions Step 1- 165

Workers in the aniline dye industry are more susceptible to bladder cancer than general population. Meanwhile, studies show that animals, when exposed to beta-naphthylamine develop liver cancer but not bladder cancer.

What is the most likely explanation of this finding?

A-Metabolism of beta-naphthylamine by human cytochrome 450 system in the liver

B-Detoxification of beta-naphthylamine by glucuronic acid conjugation.

C-Human urinary glucuronidase splits beta-naphthylamine into glucuronic acid and a toxic metabolite.

D-Beta-naphthylamine is directly carcinogenic to human bladder







Answer:

Urinary glucourinidase is found only in human. It splits beta-nephthylamine into glucuronic acid and a toxic carcinogenic metabolite.

The correct answer is C