Question

How does the liver detoxify nicotine?

a. nicotine is detoxified by reduction to cotinine which is less toxic than nicotine, and cotinine is more water soluble than nicotine, and thus more readily excreted in the urine.
b. nicotine is detoxified by condensation to cotinine which is less toxic than nicotine, and cotinine is more water soluble than nicotine, and thus more readily excreted in the urine.
c. nicotine is detoxified by oxidation to cotinine which is less toxic than nicotine, and cotinine is more water soluble than nicotine, and thus more readily excreted in the urine.

Answer 1

The liver oxidizes nicotine to cotinine, which is less toxic and more water-soluble, enabling excretion through urine as part of the liver's detoxification process. The correct answer is option c.

Step-by-step explanation:

The liver detoxifies nicotine primarily through an oxidation process. Nicotine is metabolized by liver enzymes to form several metabolites, with cotinine being the predominant one. This is crucial because cotinine is significantly less toxic than nicotine.

Additionally, cotinine has enhanced water solubility, which facilitates its excretion through urine. Detoxification mechanisms in the liver transform toxic substances into less harmful products, which are then further processed to become more readily excreted.

Nicotine is one of the substances detoxified by the liver, and its conversion to cotinine is a protective process that reduces its harmful cardiovascular effects. This is essential for individuals using nicotine replacement therapies, which aim to reduce withdrawal symptoms and assist in quitting smoking.