Uses
Nicotine, commonly found in tobacco, is one of the most popular and accepted drugs today. Throughout history, people have found new and unique ways to administer nicotine into their body. Inhalation is the most popular route of administration.
Whether it is from a pipe with pure tobacco, cigarettes, or (the newest trend) a vape, nicotine is mostly consumed through smoking/inhalation. Though nicotine is considered one of the most popular drugs, it is rarely talked about as a pesticide. Did you know nicotine can be used as a pesticide/insecticide?
Biotransformation
Nicotine is turned into hydroxylated-pyridine intermediates by bacteria. Hydroxylated-pyridine intermediates are the precursors necessary to develop insecticides.
Pictured below are different intermediates formed by degradation of nicotine.
Toxicokinetics
The toxicokinetics of nicotine are complex and can be found in an academic journal here
Mechanism of Action
Nicotine exposure/use releases dopamine by activating acetylcholine receptors that function like a4b2 subunit of nicotinic acetylcholine receptors (nAChRs) in the nucleus accumbens. Simply put, when used as a pesticide nicotine blocks synaptic transmission in the central nervous system by overstimulation of neurons.
Target Organ(s)
Nicotinic acetylcholine receptors in the (nAChRs)
Primarily the heteromeric a4b2 subunit (pictured under leter D below)
*The triangle represents the acetylcholine receptor(s) on the subunit.
Image Here
Signs & Symptoms of Toxicity
The most common symptom is vomiting (more than 50% of toxicity cases).
Short term exposure (less than 8 hours) can cause mild and severe symptoms:
Mild:
tremor, increased heart rate, respiration, bp, and alertness.
Severe:
involuntary muscle movements or seizure, abnormal heart rate/rhythm bradycardia, hypotension and paralysis of muscles in charge of breathing.
*Death may occur*
Genetic susceptibility or heritable traits
As stated above, nicotine is used as a drug among humans and genetic susceptibility to nicotine use primarily effects dependence to the substance.
Pictured below is a graph showing different candidate genes that could contribute to genetic susceptibility to nicotine dependence.
Treatments
Atropine, a common antidote for cholinergic toxicity/nicotine toxicity, is administered intravenously.
Biomarker
Cotintine is a biomarker for nicotine usage or exposure.
Found in urine, blood, hair, nails, and saliva.