Cigarette smoking Tobacco dependence

Nicotine is the main psychoactive ingredient of tobacco and is responsible for the stimulant effects and abuse/ addiction that may result form tobacco use. Cigarette smoking rapidly (in about 3 sec ) delivers pulses of nicotine into the bloodstream. Its initial effects are caused by its activation of nicotinic acetylcholine (nACh) receptors. nACh receptors are ligand-gated ion-channels and pre- and postsynaptically located. Reinforcement depends on an intact mesolimbic dopamine system (VTA). nACh receptors on VTA dopamine neurons are normally activated by cholinergic innervation from the laterodorsal tegmental nucleus or the pedunculopontine nucleus. 

Nonvolatile Nitrosamines In Tobacco Smoke. Although there are more than 10 million exsmokers in the U.S.A., 53 million adults continue to smoke cigarettes and an additional 10 million still smoke cigars or pipes (39). The cigarette smokers are exposed to about 10 ng of volatile nitrosamines, 20-40 ng of NDELA and, most importantly, to 1-10 pg of tobacco specific N-nitros-amines with each cigarette smoked (Table IV). Similar quantities of the TSNA are found in sidestream smoke. The quantities of TSNA in the smoke are dependent on nitrate, nitrite, tobacco alkaloids and on NNN, NNK and NAT in the tobacco itself (31)>... 

Nicotine The psychoactive drug found in Nicotiana tabacum that underlies cigarette smoking and tobacco dependence. 

Comer KA (1977) Dependence on cigarette smoking. 15 Dec 1977. British American Tobacco. 

In the 1970s, Murray Jarvik and others, postdated that the powerful reinforcing effects of tobacco for humans were most likely explained by substances in addition to nicotine in the tobacco and smoke (Jarvik 1977 Russell 1979). Addiction to tobacco has been designated by the nomenclature as nicotine dependence and nicotine withdrawal by the American Psychiatric Association since 1987 because of the presence of nicotine (American Psychiatric Association 1994, 1987 Stratton et al. 2001). In fact, tobacco products are complex chemical cocktails, with the modem commercial cigarette representing perhaps the most complex of all. Therefore, there is also strong merit in the approach of the WHO in its International Classification of Diseases to use the terms tobacco dependence and tobacco withdrawal. ... 

Royal College of Physicians. (2000) Nicotine addiction in Britain a report of the tobacco advisory group of the Royal College of Physicians. Royal CoUege of Physicians of London, London Russell MAH (1971) Cigarette smoking natural history of a dependence disorder. Br J Psychol 44 1-16... 

Russell MAH (1979) Tobacco dependence is nicotine rewarding or aversive In Krasnegor NA (ed) Cigarette smoking as a dependence process. NIDA Research Monograph 23. Public Health Service, US Department of Health Education Welfare, Washington, DC, pp 100-122... 

Cytotoxic effect. Gas phase of mainstream cigarette smoke, in monolayer culture of mouse lung epithelial cells, produced an increase in cytotoxicity in a dose-dependent manner. Cell viability of cultures exposed to gas phase with only the nonorganic components was equivalent to controls. Removal of volatile organic constituents resulted in almost elimination of cytotoxicity of the smoke . Smoke condensate and tobacco extract, at high concentrations in Lewis lung adenocarcinoma cells and mice spleen lymphocytes, were cytotoxic. Smaller doses increased thymidine incorporation in both cell types. Lymphocytes were more susceptible to the toxic effect of tobacco prod-... 

---