NEUR 3200 Lecture Notes - Lecture 4: Nicotiana Tabacum, Nicotiana Rustica, Nicotinic Acetylcholine Receptor
31 Oct 2017
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Document Summary
Nicotine is an alkaloid found in tobacco leaves. Large-leaf tobacco (nicotiana tabacum) and small-lead tobacco (nicotiana rustica) A typical cigarette contains 6 to 11 mg of nicotine, though no more than 1 to 3 mg actually reaches the smoker s bloodstream: bioavailability. Most nicotine is metabolized to cotinine by the liver enzyme cytochrome p450 (important for exam: cotinine not as potent but can bind to receptors, nicotine - cytp450 - cotinine. Nicotine enters the smoker s lungs on tiny particles called tar, that is known to be carcinogenic. Tar contributes to the taste and smell of cigarette smoke, and along with nicotine, these sensory qualities contribute to the reinforcing effects of smoking. Nicotine readily passes through the surface of the lungs and into the bloodstream. It is absorbed to a lesser extent through the mouth and nostrils when tobacco is chewed or snorted as snuff. Elimination half-life of nicotine is around 2 hours.
