Nicotine Nicotine is an alkaloid found in the nightshade family of plants Solanaceae , predominantly in tobacco and coca, and in lower quantities in tomato, potato, eggplant aubergine , and green pepper.
Nicotine has been found to constitute approximately 0. It functions as an antiherbivore chemical, being a potent neurotoxin with particular specificity to insects; therefore nicotine was widely used as an insecticide in the past, and currently nicotine derivatives such as imidacloprid continue to be widely used.
In low concentrations an average cigarette yields about 1 mg of absorbed nicotine , the substance acts as a stimulant in mammals and is one of the main factors responsible for the dependence-forming properties of tobacco smoking. According to the American Heart Association, "Nicotine addiction has historically been one of the hardest addictions to break.
Nicotine is named after the tobacco plant Nicotiana tabacum, which in turn is named after Jean Nicot, French ambassador in Portugal, who sent tobacco and seeds from Brazil to Paris in and promoted their medicinal use. Its chemical empirical formula was described by Melsens in , and it was first synthesized by A. Pictet and Crepieux in Nicotine is a hygroscopic, oily liquid that is miscible with water in its base form.
As a nitrogenous base, nicotine forms salts with acids that are usually solid and water soluble. Nicotine easily penetrates the skin. Because of this, most of the nicotine is burned when a cigarette is smoked; however, enough is inhaled to provide the desired effects.
As nicotine enters the body, it is distributed quickly through the bloodstream and can cross the blood-brain barrier.
On average it takes about seven seconds for the substance to reach the brain when inhaled. The half life of nicotine in the body is around two hours[3]. The amount of nicotine inhaled with tobacco smoke is a fraction of the amount contained in the tobacco leaves.
The amount of nicotine absorbed by the body from smoking depends on many factors, including the type of tobacco, whether the smoke is inhaled, and whether a filter is used.
For chewing tobacco, dipping tobacco and snuff, which are held in the mouth between the lip and gum, or taken in the nose, the amount released into the body tends to be much greater than smoked tobacco. A major metabolite is cotinine. By binding to CNS type nicotinic receptors, the nicotine molecule increases dopamine levels in the reward circuits of the brain. In this way, it activates the reward system and generates feelings of pleasure, similar to that caused by cocaine and other stimulants.
Studies have shown that smoking tobacco inhibits monoamine oxidase MAO [5], an enzyme responsible for breaking down monoaminergic neurotransmitters such as dopamine, in the brain. It is currently believed that nicotine by itself does not inhibit the production of monoamine oxidase MAO , but that other ingredients in inhaled tobacco smoke are believed to be responsible for this activity.
Furthermore, it activates the sympathetic nervous system[citation needed], acting via splanchnic nerves to the adrenal medulla, stimulates the release of epinephrine. Acetylcholine released by preganglionic sympathetic fibers of these nerves acts on nicotinic acetylcholine receptors, causing the release of epinephrine and norepinephrine into the bloodstream. Psychoactive effects Nicotine's mood-altering effects are different by report. First causing a release of glucose from the liver and epinephrine adrenaline from the adrenal medulla, it causes stimulation.
Users report feelings of relaxation, calmness, and alertness. It is even reported to produce a mildly euphoric state.
By reducing the appetite and raising the metabolism, some smokers may lose weight as a consequence. The tobacco industry grew throughout the s, and exploded in when a machine was first patented to mass-produce paper cigarettes. From then on, cigarettes became much easier to produce, and this saw in the dawn of the major tobacco corporations. In , Wilhelm Heinrich Posselt, a doctor, and Karl Ludwig Reinmann, a chemist, both from Germany, first isolated nicotine from the tobacco plant and identified it as a poison.
By the end of the 19th century, lawmakers had begun to realize the harmful effects of nicotine. Laws were passed banning stores from selling nicotine to minors in 26 states by the year It was not until that the Surgeon General of the U. The U.
Food and Drug Administration FDA took until to officially recognize nicotine as a drug that produced dependency. Even after this landmark recognition, the FDA was not granted control over nicotine regulations by the Supreme Court until June 22nd, This surge of adrenaline stimulates the body.
There is an immediate release of glucose, as well as an increase in heart rate, breathing activity, and blood pressure. Nicotine also makes the pancreas produce less insulin , causing a slight increase in blood sugar or glucose. Indirectly, nicotine causes the release of dopamine in the pleasure and motivation areas of the brain.
A similar effect occurs when people take heroin or cocaine. The drug user experiences a pleasurable sensation. Dopamine is a brain chemical that affects emotions, movements, and sensations of pleasure and pain. If your brain dopamine levels rise, the feeling of contentment is higher. When humans, mammals, and most other types of animals are exposed to nicotine, it increases their heart rate, heart muscle oxygen consumption rate, and heart stroke volume.
These are known as pharmacologic effects. Consuming nicotine is also linked to raised alertness, euphoria, and a sensation of being relaxed. Studies have shown that nicotine appears to improve memory and concentration. It is thought that this is due to an increase in acetylcholine and norepinephrine. Norepinephrine also increases the sensation of wakefulness, or arousal. Nicotine results in increased levels of beta-endorphin, which reduces anxiety.
People who regularly consume nicotine and then suddenly stop experience withdrawal symptoms, which may include:. The American Heart Association says that nicotine consumed from smoking tobacco is one of the hardest substances to quit. It is considered to be at least as hard as quitting heroin. A study showed that reducing the amount of nicotine in cigarettes also brings down their level of addictiveness.
A study carried out at the National Institute on Drug Abuse found that nicotine consumption makes cocaine more addictive. If a woman smokes while pregnant, the following risks are likely in the development of the child:.
This will mean a lot for our ability to bring you news, perspectives and analysis from the ground so that we can make change together. Please use a genuine email ID and provide your name. Curbing nicotine dependence The cure for problems like drug addiction and Parkinsons disease can be found but not before some unknown ingredients in cigarette smoke are isolated Published: Tuesday 30 April Subscribe to Weekly Newsletter :.
Donate Now. Post a Comment. Please Sign In to post a comment. The news made headlines in Smokers today get more nicotine from inhaling cigarette smoke than they did in The news is alarming because nicotine is the chemical in cigarette smoke that causes addiction to tobacco. The Massachusetts Department of Public Health DPH reported its discovery that the nicotine yield in cigarettes—meaning the amount of nicotine a smoker gets from a cigarette—had increased steadily between and The DPH used information provided by tobacco companies themselves.
Massachusetts is one of only three states in the country to require tobacco companies to report this information each year. One deadly consequence of more nicotine yield in cigarettes is that the average smoker will find it harder to quit.
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