What is nicotine
Everyone knows about the dangers of smoking. But what is nicotine in terms of chemistry and pharmacology, what properties does this infamous substance possess, a drop of which kills a horse?
The word "nicotine" originates from the Latin name for tobacco, Nicotiana tabacum. The plant is obliged to them to the French ambassador at the court of Portugal, and in combination to the scientist, Jean Nico, who recommended tobacco to Catherine de Medici as a remedy for a headache. Later, Niko brought a plant from Portugal to France and studied its properties.
In the Middle Ages, alchemists learned how to get pure nicotine by distilling tobacco leaves. Brown oily liquid was used to treat skin diseases, asthma, epilepsy, inflammation of the spleen.
The main scientific discoveries related to nicotine were made in the first half of the 18th century and belong to the German chemists Christian Wilhelm Posselt, Karl Ludwig Rymann, Louis Melsen, Adolf Pierin. Nicotine was synthesized chemically in 1893.
Nicotine - what is it
Nicotine - what is this chemical? It belongs to the group of alkaloids - plant nitrogen-containing compounds with the properties of weak alkalis. This group includes strychnine, caffeine, quinine, cocaine and other drugs and poisons isolated from plants by humans, and later synthesized artificially. Many alkaloids have a certain effect on the nervous system of humans and animals.
Nicotine is a colorless, oily liquid with a pungent odor and burning taste. When storing acquires a yellowish-brown color. In the Middle Ages, alchemists called it “tobacco oil”. The density of nicotine is approximately equal to the density of water, it mixes well with it. With acids, it also forms salts that are highly soluble in water. The chemical formula of nicotine: C10H14N2 (pyridin-3-N-methylpyrrolidine).
Nicotine is extremely toxic to cold-blooded animals and insects. At the beginning of the twentieth century it was widely used as an insecticide for protection against pests. Later, due to the negative impact of the drug on humans and warm-blooded animals, artificial derivatives, imidacloprid, acetamiprid, replaced it.
Where does nicotine
Nicotine is an alkaloid found in plants of the solanaceous family (Solanaceae). The largest amount is contained in tobacco leaves. Synthesis of substances produced in the roots, and accumulation - in the leaves of the plant. The alkaloid content in dry tobacco is 0.3–5% by weight of raw materials. Other plants of the nightshade family contain it in smaller quantities:
- green pepper.
Does the human body produce nicotine? No, this substance is not involved in normal metabolism. However, under the influence of enzymes, it is oxidized to nicotinic acid, known as vitamin PP (antipellagic). Unfortunately, such an enzyme is absent in the human body and this transformation is impossible.
The effect of nicotine on the human body
Nicotine has a good affinity for all tissues of the human body. It is absorbed by the lungs from tobacco smoke, through the mucous membranes of the mouth, from the stomach and intestines, in contact with the skin. Entering the blood, quickly spreads through all organs, penetrates through the brain barrier, through the placenta and other biological membranes.
When inhaled, this drug is found in the brain after 4–7 seconds. The peak concentration in the blood is reached 10 minutes after smoking a cigarette and decreases twice in half an hour. During this time, the brain is cleared of the drug.
How much nicotine is kept in the blood and provides a narcotic effect? Its content returns to its original amount in 2–3 hours, and the substance is completely eliminated from the body in about two days. Through how much nicotine comes out of the human body can be traced by a specific marker, which is cotinine. The fact is that in the liver the drug is split into two molecules - cotinine and nicotine-N-oxide. The kidneys excrete these inactive metabolites in the urine. A simple test has been developed to determine cotinine in the urine 1.5–2 days after smoking a cigarette, which can serve as an indicator of the presence of an addiction.
The effect of nicotine on the human body is determined primarily by its effect on the nerve compounds - synapses. In low concentrations, it stimulates the release of a mediator in acetylcholine receptors, which leads to a number of effects:
increased adrenaline production;
- increased heart rate;
- vasoconstriction and increased blood pressure;
- the flow of glucose from the liver into the blood;
- the release of neurotransmitters in the brain, leading to a psychostimulating effect.
When the dose is increased, it blocks nerve synapses, which is manifested by the depression of the central nervous system and a number of negative symptoms .
Nicotine is a drug, it causes physical and mental dependence. Rapid addiction is developing to it - the requirement to increase the dose to achieve a narcotic effect. The question of whether a person gets pleasure directly from a drug remains open, because the substance in a certain way affects the dopamine mediators in the brain, which are responsible for the pain threshold and pleasure center. According to another version, such an effect does not have the drug itself, but the substances contained in tobacco smoke.
In patients with schizophrenia, an increased craving for tobacco has been observed. The question is not completely clear - there are a number of hypotheses regarding the causes of this addiction.
This is a very toxic substance. The lethal dose of nicotine for humans is 0.5–1 mg / kg, for mice it is 0.8 mg / kg when administered into a vein and 5.9 mg / kg intraperitoneally, for rats it is 50 mg / kg by mouth and 140 mg / kg when applied to the skin. For comparison: the lethal dose of potassium cyanide is 1.7 mg / kg. When smoking, most of the drug volatilizes with smoke, and 20–30% enters the lungs. When chewing tobacco, this percentage is higher, but the flow of toxin into the human body is slower, so the peak blood concentrations are lower than in smokers. On average, when smoking one cigarette a person gets 1 mg of nicotine. For teenagers and children, an attempt to smoke even half a pack of cigarettes in a short time (2-4 hours) can be deadly. The cause of death in nicotine overdose is respiratory arrest due to paralysis of the respiratory center, cardiac arrhythmia, or severe suppression of the central nervous system (coma).
Nicotine poisoning in overdose is manifested by the following symptoms:
- apathy or overexcitement;
- cold sweat;
- dizziness, tinnitus, blurred vision;
- excessive salivation;
- nausea, vomiting;
- shallow rapid breathing;
Nicotine harm to the human body is very diverse. A nervous, cardiovascular, digestive system is affected, the general metabolism and respiratory organs are affected. Here are the diseases typical for smokers:
- cardiac ischemia;
- angina pectoris;
- myocardial infarction;
- obliterating endarteritis;
- peptic ulcer;
In combination with harmful substances of tobacco smoke, nicotine affects the respiratory system, causing such diseases:
- chronic inflammation of the larynx;
- laryngeal cancer;
- lungs' cancer.
Toxin contributes to the development of inflammation of the gums and oral mucosa, cancer of the tongue.
The substance is recognized by all scientific communities, as a life-threatening toxin and drug. Is it possible to get the benefits of nicotine as a drug? After all, it is no secret that many vegetable alkaloids, including drugs, have been used previously or are used to this day as medications. Currently, funds are being released to alleviate the withdrawal syndrome in ex-smokers - nicotine patches, chewing gums and the like. They have many contraindications. So, they can not be applied to pregnant and lactating, patients with heart disease and peptic ulcer.
In a number of countries, laboratory studies are being conducted in which this alkaloid acts as a means for the prevention and treatment of:
attention deficit disorder;
- Alzheimer's disease;
- peptic ulcer disease;
- Parkinson's disease.
So, perhaps, in the near future, nicotine will be part of drugs for a variety of diseases.
Summarizing all the above, we can draw the following conclusions. Nicotine is a plant alkaloid that has a narcotic effect and acts on the human nervous system through the acetylcholine receptors of nerve compounds. What does nicotine affect? It has a psychostimulant effect, is addictive and addictive. Smokers with experience develop pathologies of the nervous, cardiovascular, digestive and respiratory systems. The only reasonable and effective treatment of such diseases is to stop the drug from entering the body.