Nicotine reacts with and binds to several sites in the nervous system in humans. The effects are different in the brain (central nervous system) and in the body (peripheral nervous system). In the brain, nicotine influences the pleasure centers slightly. It doesn’t act directly, but rather to increase the effects of other neurotransmitters.
Peripherally, nicotine’s main effects are on the adrenal glands, where they stimulate release of small amounts of adrenalin. This is one reason why cigarette smoking increases heart rate and blood pressure and decreases appetite.
Overall effects of nicotine
The effects in the brain seem to counteract the stimulus from the adrenal glands and nicotine addicts may at times find a cigarette relaxing and at other times find it seems to energize them. This may also be partly explained by the psychological habit of smoking – the simple, comfortable act of doing a habitual behavior might help explain why smoking relaxes people. For example, smoking has become associated with taking a break from work.
At higher doses, nicotine begins to affect receptors in muscle tissue. This can lead to toxicity and death from muscle paralysis and suffocation. Nicotine is used as an insecticide for this reason. At mid-range doses, nicotine causes dizziness, nausea, and vomiting.
Absorption of the drug occurs in the lungs or through the thin membranes of the mouth. About a milligram is absorbed with each cigarette. The amount of nicotine in cigarettes has been increasing across all major brands by about 1.6% a year.1
Possible therapeutic uses for nicotine
Scientists are investigating an interesting link between cigarette smoking and schizophrenia. The startling statistic - that from 70% to 90% of schizophrenics smoke - suggests they might be getting some benefit from nicotine. Drugs that mimic nicotine’s effects are being studied to see if they may offer a treatment without the harmful effects of smoking.
For more information on schizophrenia and smoking please visit Schizophrenic.com
Nicotine has also been shown to delay the onset of Parkinson’s disease and is useful in treating a particular type of sleep-epilepsy.
photo by Karol Stroz
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References
- 1998 – 2005, see: Harvard School of Public Health Report
