Nicotine: what it is, its characteristics and how it affects our organism.

These are the characteristics and effects of nicotine, one of the most consumed drugs in the world.

The World Health Organization (WHO) estimates that there are more than 1.3 billion tobacco smokers worldwide. Beyond this alarming figure, if we delve into medical terms, things get drastically worse: up to half of those who use tobacco end up dying. Lung cancer clearly exemplifies this fact, since it is responsible for 25% of neoplastic processes in humans and claims more than 130,000 deaths a year.

As much as we are all aware of the harm caused by this addiction, tobacco consumption is still completely normalized in some countries. Without going any further, it is estimated that in regions such as Spain, 24.5% of the adult population smokes, with all the psychological, social and physiological effects that this entails.

Beyond numbers, lung cancer, health and other topics, tobacco is fascinating from a physiological point of view. Today we tell you all about its key component: nicotine.

What is nicotine?

Nicotine, with the chemical name (S)-3-(1-methylpyrrolidin-2-yl) pyridine, is an alkaloid found in the brain. an alkaloid found mainly in the tobacco plant (Nicotiana tabacum). It is a secondary metabolite produced by the plant from amino acids, which is why it contains nitrogenous compounds in its chemical formula. Tobacco is not the only alkaloid known and used by humans: cocaine and caffeine are also examples.

Nicotine is mainly stored in the leaves of the plant, accounting for 5% of its total dry weight.. This has a clear biological function: the compound is a pesticide that prevents certain invertebrates from preying on the leaves. In addition to this, herbicidal properties are also attributed to it, which reduces the growth of other plants near the tobacco, thus causing the plant to have a greater availability of resources.

In addition to the well-known tobacco plant (Nicotina tabacum), there are other plants that synthesize this alkaloid in varying concentrations.. Among them, we find the following:

• Among some plants that contain little nicotine are the equisetum, celery, potato plant and even the papaya plant.
• The tobacco tree (Nicotina glauca) does not have much nicotine, although it is rich in the alkaloid anabasine, a nicotinic receptor agonist.
• Mapacho (Nicotina rustica) has higher amounts of nicotine than the normal tobacco plant. For this reason, the ingestion of its leaves in excess is considered dangerous.

As you can see, not only the typical tobacco plant contains nicotine. After all, we are talking about a pesticide and herbicide alkaloid that can bring many benefits to the plant when it comes to surviving in the environment.

A cigarette contains on average 12 milligrams of nicotine, although these values can vary from 8 to 20 milligrams.. As a curious fact, it is worth noting that the content of 4 cigarettes (50 mg of nicotine) is capable of killing a man, if the compound is injected intravenously. Therefore, we are not surprised to learn that several serious intoxications have occurred in infants due to direct ingestion of the contents of cigarettes.

Actions of nicotine on the organism

According to studies, nicotine is a substance with stimulant properties and is responsible for cigarette dependence. The main human brain structures involved in this addiction mechanism are the nucleus accumbens, the prefrontal cortex, the hippocampus and the amygdala. This alkaloid produces direct (and indirect) actions on neurotransmitters, such as dopaminesuch as dopamine, acetylcholine, noradrenaline and serotonin.

When a low dose of nicotine is administered to humans, it produces a sensation of instant gratification. instant gratification, as endorphins are released in the brain's gratification circuits. endorphins are released in the brain's gratification circuits. As with other drugs, the feelings of reward and euphoria are positively correlated with the release of the neurotransmitter dopamine, which generates the compulsive need to consume the drug again.

In addition to these quantifiable brain effects, nicotine encompasses many more frames of action in the human body. Among them, we find the following:

• Decreases appetite: nicotine helps weight loss because it interacts with enzymes related to appetite and intake. Many tobacco users drastically gain weight when quitting the drug.
• Increases intestinal activity.
• Causes the formation of more saliva and phlegm: this is a product of irritation of the upper respiratory tract.
• Increases heart rate and Blood pressure.
• Stimulates memory and wakefulness: for this reason, chronic smokers feel they need to smoke in order to concentrate and be active.

After inhaling tobacco smoke, the concentration of nicotine in the blood increases rapidly and, in less than 20 seconds, the nicotine concentration in the blood increases. and, in less than 20 seconds, it reaches the brain and activates the reward mechanisms described above. Surprisingly enough, inhaled through tobacco smoke, this alkaloid reaches its destination sooner than if it is administered intravenously.

Unfortunately, nicotine acts as fast as it disappears. This alkaloid reaches its peak activity within 10 seconds, so it produces a brief and rapid gratification, but of a mild nature. For this reason, a smoker requires the consumption of several cigarettes a day to feel completely well and to focus his or her attention on the tasks at hand. and focus his or her attention on the relevant tasks.

It is when smoking is stopped that the neurological hecatomb occurs: continued smoking causes the secretion of exceptionally low levels of dopamine as nicotine concentrations in the central nervous system are depleted. This undoubtedly underlies the dangerous bases of dependence that this substance generates.

Physical and psychological addiction

To understand the mechanism of nicotine addiction, it is essential to differentiate the physical from the physiological, although the two fronts are largely interconnected.

Physical dependence is that which occurs when symptoms manifest themselves a few days/hours after the drug in question has been withdrawn from the patient's life. from the patient's life. Mild clinical signs usually appear 2-3 hours after the last cigarette, peaking 2-3 days later.

These include headaches, tension, anxiety, depression, difficulty concentrating and a strong urge to put a cigarette in the mouth.. It should be noted that physical dependence is largely conditioned by tolerance: the less sensitive the body is to the substance, the more it is needed.

On the other hand, psychological addiction refers to the need for the pleasure generated by the substance or, alternatively, how it helps the patient to cope with his or her problems. Both events are largely interconnected, as they lead to the same symptoms described above.

Is it difficult to quit smoking?

Any reader who has tried (or succeeded) in quitting smoking will know the answer to this question. Shocking as it may seem, the chances of becoming dependent on tobacco (28%) are greater than on cannabis (8%) or cocaine (11%). While other drugs are more clearly deleterious in the short term, tobacco kills slowly but unstoppably.

Most smokers try to quit on average 2 times before quitting for good.. In addition, 25% of those who try to quit are unable to go more than 24 hours without putting a cigarette in their mouth. Such is the degree of addiction that more than half of the patients who have undergone lung cancer surgery return to smoking at some point in their lives. In these cases, addiction clearly prevails over craving.

Summary

Without a doubt, we are facing one of the most problematic drugs in the world, we are faced with one of the most problematic drugs (if not the most problematic) in today's society.. The World Health Organization backs up this statement with data that fall like a vase of cold water: tobacco kills up to 1 out of every 2 people who use it.

For all these reasons, lung cancer is one of the most common malignant tumors worldwide. To make matters worse, this type of cancer is one of the most deadly, as the patient's survival rate 5 years after diagnosis is less than 20%. After reading these lines, there is little doubt that starting to use tobacco is one of the worst decisions you can make in life.

Bibliographic references:

• Is nicotine addictive? National Institute of Drug Abuse (NIH). Retrieved January 29 at https://www.drugabuse.gov/es/publicaciones/serie-de-reportes/adiccion-al-tabaco/es-adictiva-la-nicotina.
• Campo, A. (2002). Nicotine dependence: approach to its pharmacological management. Rev. colomb. psychiatr, 67 - 72.
• La nicotina, pfitzer.es Retrieved January 29 at https://www.pfizer.es/salud/dejar_de_fumar/nicotina.html.
• Nicotine and tobacco, Medlineplus.gov. Retrieved January 29 from https://medlineplus.gov/spanish/ency/article/000953.htm.
• Secades Villa, R., & Fernández Hermida, J. R. (2001). Effective psychological treatments for drug addiction: nicotine, alcohol, cocaine and heroin. Psicothema, 13 (3).
• Tobacco, WHO. Retrieved January 29 at https://www.who.int/es/news-room/fact-sheets/detail/tobacco.