What is Nicotine:
Nicotine comes from the tobacco plant. Tobacco is the name of the plants of the genus Nicotiana of the Solanaceae Family or NightShade Family. Where many different species of tobacco plants existe and have different properties when smoked.
Tobacco was first brought to Europe during the years of exploration and colonization of America. Near the end of the 16th Century, tobacco was used all over the world. Throughout the years, many different methods of smoking have arose such as the pipe, the cigarette,the bong and the vape. Smoking was first advertised and used primarily by men but during World War II, women started to use cigarettes as well. In 2017, 14.3% of women and 18.6% of men smoke in the USA. During the 20th century, smoking was at its prime in the US and people were told that it wasn’t harmful. But research by the 1940 proved that there was such a high correlation between smoking and cancer. But Big Tobacco denied such issue till 1999 and even tried to discredit the research by conducting their own. But in 1964, the surgeon general released his report confirming that cigarettes cause serious health issues and cancer. This lead to numerous changes in legislation and campagnes to prevent smoking by bringing awareness and knowledge to the people.
Pharmacokinetics of Nicotine:
3 different routes of administration
- Absorption from mouth and digestive system
Half life is about 1 – 3 hours
20% of the population have a genetic defect in their bodies capability in metabolizes nicotine which raises the half life that the drug spends in the body.
Effects on the body:
Increases the heart rate and blood pressure which gives the initial headrush feeling because it is more blood being rushed into the brain. However, it is a vasoconstrictor which means that it constricts the blood vessels in the skin. This has an effect of dropping our bodies temperature and reduces blushing. It stimulates bowel activity and can cause nausea. Finally, at high doses of nicotine in the body it can cause muscle tremors most commonly in the arms but also the body in general.
Effects on the Brain:
Nicotine binds to the nicotinic Ach receptor. They are found widely in the PNS and CNS. They can cause a release of Neurotransmitters by allowing Ca2+ to enter presynaptically or can cause EPSPs by allowing Na+ and K+ to enter the neuron. There have been 12 different subunits listed from A2 to A10 and B2 to B4 which have a numerous amount of combination which can have a diverse range of pharmacological and electrophysiological properties. Each receptor is made up of different subunits either homomeric receptor or heteromeric receptor. Two receptors that have an important role when activated are the a4b2 nAChr and the a5 nAChr receptors. The a4b2 receptors cause the increase of dopamine in the mesoaccumbens pathway which is the main cause for addiction because everytime there is an intake of nicotine there is an increase of dopamine and likelihood of you hitting it again. The a5 receptors are mainly in the habenula which cause us to feel disgust and nausea since nicotine is a toxin. This is the way the brain protects itself from poisoning itself off of the drug since it makes you not want to hit anymore nicotine.