Nicotine Yields Of Cigarettes Research Articles

Nicotinic Receptor Alpha-5 Subunit Gene Polymorphism is Associated with Heavy Smoking Under a Range of Nicotine Dosing Conditions.

This study aimed to assess the role of the rs16969968 variant of nicotinic receptor alpha-5 subunit in regulating smoking behavior and nicotine intake in response to nicotine manipulations among dependent smokers in a naturalistic environment. Sixty-nine adults (19 females) smoking 10 or more cigarettes per day were asked to complete four 2-week study phases during which they smoked exclusively one of two types of Spectrum nicotine research cigarettes (FTC nicotine yield 0.8 and 1.6mg, respectively), their usual brand of cigarettes, or their usual brand of cigarettes while wearing a 21-mg nicotine patch. Measurements included rs16969968 genotype, number of cigarettes per day, smoking topography, and plasma cotinine. Compared to controls (G/G carriers), A allele carriers reported smoking 4 to 5 more cigarettes per day across all conditions (all ps < .05). Mean total smoke volume per day and cotinine were greater in A allele carriers than in controls (ps = 0.05, 0.046, respectively). No significant genotype differences were found in smoking compensation indices for the switch from Medium to High nicotine yield cigarettes. Nicotine patch-induced reductions in cigarettes smoked per day and total smoke volume per day showed significant interactions between genotype and pre-patch levels, heavier smokers showing greater effects of genotype (p = .052 and p =.006, respectively). Results suggest that the rs16969968 variants regulate heaviness of smoking primarily by their impact on daily numbers of cigarettes smoked, but no genotype differences were found in smoking compensation after switching from Medium to High nicotine cigarettes. The differences in daily cigarette consumption between rs16969968 risk-allele carriers and controls are shown to be consistent regardless of manipulations of cigarette nicotine content and transdermal nicotine supplementation and markedly greater among dependent smokers than those observed in the general smoker populations. G/G allele carriers, relative to A allele carriers, appeared to be more sensitive to the nicotine patch manipulation, reducing their smoking to a greater extent. These findings support continued efforts in the development of personalized intervention strategies to reduce the rs16969968-conveyed genetic propensity for heavy smoking.

Comparison of smoking cessation rates of Quitline users in Korea between smokers of ultra-low nicotine yield cigarettes and other types of cigarette: a prospective study.

AimsIt is not known whether the machine‐smoked nicotine yield of usual brand of cigarette smoked is associated with the chances of success of quit attempts. This study aimed to assess this association.DesignProspective study.SettingRepublic of Korea.ParticipantsA total of 16 808 male smokers registered for the Quitline between 7 April 2006 and 31 December 2013. Of these, 13 176 participants who were > 19 years of age and provided data on their demographic characteristics, smoking‐related behaviors, nicotine dependence, tobacco brands used and self‐efficacy were included in this study.MeasurementsMachine‐smoked nicotine yield was based on information provided by tobacco companies on cigarette packages that smokers reported as their usual brand. Ultra‐low nicotine yield was defined as ≤ 0.1 mg machine‐smoked nicotine yield per cigarette, whereas higher nicotine yield was defined as > 0.1 mg machine‐smoked nicotine yield. Participant personal information and self‐reported continuous abstinence at 1‐month, 6‐month and 1‐year follow‐up were recorded in electronic databases.FindingsContinuous abstinence rates in the ultra‐low nicotine yield versus higher nicotine yield groups were, respectively, 40.7 versus 34.6% at 1 month [odds ratio (OR) = 1.22, 95% confidence interval (CI) = 1.12–1.33], 22.7 versus 18.8% at 6 months (OR = 1.20, 95% CI = 1.08–1.32) and 19.5 versus 16.6% (OR = 1.19, 95% CI = 1.10–1.29) at 1 year. The association between ultra‐low nicotine yield cigarette smoking and successful quitting was stronger among the smokers with higher cigarette dependence.ConclusionsMale smokers who use the Korean Quitline are more likely to quit successfully if they smoke ultra‐low nicotine yield cigarettes than if they smoke higher nicotine yield cigarettes.

Low Nicotine Content Descriptors Reduce Perceived Health Risks and Positive Cigarette Ratings in Participants Using Very Low Nicotine Content Cigarettes.

Understanding how smokers perceive reduced nicotine content cigarettes will be important if the FDA and global regulatory agencies implement reduced nicotine product standards for cigarettes. Prior research has shown that some smokers incorrectly believe "light" cigarettes are less harmful than regular cigarettes. Similar misunderstandings of health risk could also apply to reduced nicotine cigarettes. To date, most studies of reduced nicotine cigarettes have blinded subjects to the nicotine content. Therefore, little is known about how smokers experience reduced nicotine content cigarettes when they are aware of the reduced content, and how use may be impacted. The present study was a within-subjects experiment with 68 adult daily smokers who smoked two identical very low nicotine content Quest 3 (0.05 mg nicotine yield) cigarettes. Subjects were told that one cigarette contained "average" nicotine content, and the other contained "very low" nicotine content. After smoking each cigarette, subjects completed subjective measures about their smoking experience. Subjects rated the "very low" nicotine cigarette as less harmful to their health overall compared to the "average" nicotine cigarette; this effect held true for specific smoking-related diseases. Additionally, they rated the "very low" nicotine cigarette as having less desirable subjective effects than the "average" nicotine cigarette and predicted having greater interest in quitting smoking in the future if only the "very low" nicotine cigarette was available. Explicit knowledge of very low nicotine content changes smokers' perceptions of very low nicotine content cigarettes, resulting in reduced predicted harm, subjective ratings and predicted future use. Before a reduced nicotine product standard for cigarettes can be implemented, it is important to understand how product information impacts how smokers think about and experience very low nicotine content cigarettes. Prior research has shown that smokers incorrectly believed light cigarettes were less harmful products. As such, smokers may also misunderstand the health risks associated with smoking very low nicotine content cigarettes. This study highlights the importance of smokers' perceptions of nicotine content in cigarettes on the perceived health risks and the subjective effects of smoking very low nicotine content cigarettes.

Comparison between smoking topography and urinary biomarkers of Japanese smokers

Introduction: Although Japanese smokers prefer the low nicotine yield cigarette (nicotine 0.1-0.5 mg) in compared with other countries, few reports have studied the relationship of smoking patterns...

Longitudinal study of long-term smoking behaviour by biomarker-supported determination of exposure to smoke

BackgroundLong-term studies of smokers who switch to lower nicotine yield cigarettes have been identified by the World Health Organization Study Group TobReg and the US Food and Drug Administration as one key area where new knowledge is required to guide science based regulation. The limited number of long-term switching studies have concluded that smokers who switch to lower nicotine yield cigarettes show evidence of partial compensation. Since the European Union tobacco product directive of 2001 introduced tar and nicotine yield ceilings, there has been no long-term observational switching study. To address the limitations of previous studies where smokers were forced switched for relatively short durations, we plan to undertake a long-term study of spontaneous switching which is appropriately powered and includes non-switchers as a control group.Methods/designHealthy adult smokers aged 21–64 years will be enrolled into this 5-year non-residential, multicentre study across 10 cities in Germany. They will be assessed at 10 timepoints with 6 month intervals during which inclusion criteria will be reassessed and spent cigarette filter tips, saliva and 24 h urine samples will be collected. These samples will be used to determine average daily cigarette consumption, estimate mouth-level exposure to tar and nicotine and measure selected biomarkers of exposure, respectively. Spontaneous changes in subjects’ preferred cigarette products and any consequent change in tar or nicotine yield will be monitored. Subjects will be required to complete questionnaires on quality of life, smoking behaviours, smoking-related sensory attributes and recent life changes.DiscussionThe planned study is anticipated to contribute to understanding smokers’ behaviours and their consequent exposure to smoke constituents. It will also allow assessment of compensatory changes in their behaviour following spontaneous switching of cigarette product smoked. Data from this study are expected to provide insights into study design and conduct for non-clinical assessment of smokers’ exposure as part of post marketing surveillance programmes.Trial registrationCurrent Controlled Trials Database reference ISRCTN95019245.

Sex differences in response to reduced nicotine content cigarettes

BackgroundWhen switching from usual brand cigarettes, very low nicotine content (VLNC) cigarettes lead to a reduction in the number of cigarettes smoked, toxicant exposure, withdrawal symptoms and dependence. One area that has been relatively unexplored is what factors might moderate the effects of VLNC cigarettes. This exploratory analysis focuses on sex differences in responses to VLNC cigarettes and nicotine replacement therapy. MethodsAn exploratory secondary analysis of a randomized trial of 235 participants (58% female, mean age 47years) comparing a) 0.05–0.09mg nicotine yield cigarettes; b) 21mg nicotine patch and 3) 0.05–0.09 nicotine yield cigarettes with 21mg nicotine patch was conducted. We focused on sex differences in product use, and impact of products on withdrawal response from usual brand cigarettes and abstinence by randomized group. ResultsThe combination of VLNC cigarettes and nicotine patch was more effective in reducing use of VLNC cigarettes and withdrawal symptoms among males than females, whereas females were equally responsive to VLNC cigarettes with and without the nicotine patch. Females were more likely to quit smoking than males when assigned to either of the conditions that incorporated the VLNC cigarettes; however, males were more likely to quit smoking in the nicotine patch alone condition than females. ConclusionSex of the smoker may be an important determinant for effects of VLNC cigarettes and nicotine patch. Future large randomized trials to confirm these results are needed.

Reduced Nicotine Content Cigarettes and Nicotine Patch

Reduced nicotine content (RNC) cigarettes have led to smoking fewer cigarettes, withdrawal relief, and facilitation of cessation. The aim of this study is to examine the effects RNC cigarettes with and without nicotine patch and patch alone on smoking behavior, toxicant exposure, withdrawal discomfort, and as an exploratory analysis, on long-term abstinence. This study involved a randomized, parallel arm design and six weeks of: (i) 0.05-0.09 mg nicotine yield cigarettes (N = 79); (ii) 21 mg nicotine patch (N = 80), or (iii) 0.05-0.09 nicotine yield cigarettes with 21 mg nicotine patch (N = 76); all groups received six weeks of additional behavioral treatment with follow-ups up to six months. Combination approach led to lower rates of smoking assigned cigarettes and hence lower carbon monoxide levels than RNC cigarettes alone. In addition, the combination approach was associated with less withdrawal severity when switching from usual brand to assigned product, and less smoking of usual brand cigarettes during treatment, but not after treatment compared with the other approaches. Combining very low nicotine content cigarettes with nicotine patch may improve the acute effects resulting from switching to either of these products alone. These findings may have implications for smoking cessation treatment or a policy measure to reduce nicotine content in cigarettes.

Smoking topography and biomarkers of exposure among Japanese smokers: associations with cigarette emissions obtained using machine smoking protocols

Although the relative risk of lung cancer due to smoking is reported to be lower in Japan than in other countries, few studies have examined the characteristics of Japanese cigarettes or potential differences in smoking patterns among Japanese smokers. To examine tar, nicotine and carbon monoxide (TNCO) emissions from ten leading cigarettes in Japan, machine smoking tests were conducted using the International Organization for Standardization (ISO) protocol and the Health Canada Intense (HCI) protocol. Smoking topography and tobacco-related biomarkers were collected from 101 Japanese smokers to examine measures of exposure. The findings indicate considerable variability in the smoking behavior of Japanese smokers. On average, puffing behaviors observed among smokers were more similar to the parameters of the HCI protocol, and brands with greater ventilation that yielded lower machine values using the ISO protocol were smoked more intensely than brands with lower levels of ventilation. The smokers of "ultra-low/low" nicotine-yield cigarettes smoked 2.7-fold more intensively than those of "medium/high" nicotine-yield cigarette smokers to achieve the same level of salivary cotinine (p=0.024). CO levels in expiratory breath samples were associated with puff volume and self-reported smoking intensity, but not with nominal values of nicotine-yield reported on cigarette packages. Japanese smokers engaged in "compensatory smoking" to achieve their desired nicotine intake, and levels of exposure were greater than those suggested by the nominal value of nicotine and tar yields reported on cigarette packages.

Conversation with Martin Jarvis

Conversation with Martin Jarvis

Reduced nicotine content cigarettes: effects on toxicant exposure, dependence and cessation

To examine the effects of reduced nicotine cigarettes on smoking behavior, toxicant exposure, dependence and abstinence. Randomized, parallel arm, semi-blinded study. Setting University of Minnesota Tobacco Use Research Center. Six weeks of: (i) 0.05 mg nicotine yield cigarettes; (ii) 0.3 mg nicotine yield cigarettes; or (iii) 4 mg nicotine lozenge; 6 weeks of follow-up. Measurements Compensatory smoking behavior, biomarkers of exposure, tobacco dependence, tobacco withdrawal and abstinence rate. Unlike the 0.3 mg cigarettes, 0.05 mg cigarettes were not associated with compensatory smoking behaviors. Furthermore, the 0.05 mg cigarettes and nicotine lozenge were associated with reduced carcinogen exposure, nicotine dependence and product withdrawal scores. The 0.05 mg cigarette was associated with greater relief of withdrawal from usual brand cigarettes than the nicotine lozenge. The 0.05 mg cigarette led to a significantly higher rate of cessation than the 0.3 mg cigarette and a similar rate as nicotine lozenge. The 0.05 mg nicotine yield cigarettes may be a tobacco product that can facilitate cessation; however, future research is clearly needed to support these preliminary findings.

Do Reductions in the Tar and Nicotine Yields of Cigarettes Help to Explain Recent Reductions in Lung Cancer Rates in Young Men and Women in the United States?

Between 1985 and 2000, lung cancer rates in U.S. men and women aged 35–54 yr have declined. To investigate whether these declines can adequately be explained by changes in smoking prevalence, consumption, and duration, or if changes in tar and nicotine yields also contributed, two model-fitting approaches were used. Both approaches used individual person National Health Interview Survey data on smoking prevalence, age of starting and time of quitting, and national estimates of consumption per smoker and yields. Both approaches compared observed rates (by sex and age) relative to 1985, with those predicted after successively including various smoking variables into the model, making varying allowance for compensation for reduced yield. Approach A was simpler, based on mean smoking statistics estimated separately for current and former smokers. Approach B used the multistage model and individual smoking histories to estimate risk. Both approaches showed observed declines in risk were (except for men aged 35–39 yr) clearly greater than predicted based only on prevalence, consumption, and duration. Including yield generally improved the fit. At younger ages, models assuming substantial compensation (consistent with evidence from studies relating nicotine yield and intake) fitted well, but at age 50–54 yr in both sexes and age 45–49 yr in women, the decline was better fitted by models assuming little compensation. The conclusions were not sensitive to the precise parameter values assumed in the modeling. Interpretation is not straightforward, but the findings suggest declines in yields have contributed to the recent declines in rates in young U.S. men and women.

Regional cerebral blood flow and plasma nicotine after smoking tobacco cigarettes

The hypothesis for this research is that only in some brain areas, regional cerebral blood flow (rCBF) after tobacco smoking is correlated with arterial plasma nicotine concentrations. Twenty-one healthy adult tobacco smokers of both genders were studied after overnight tobacco abstinence. H 2 15O water was used to measure rCBF. Six separate scans were taken about 12 min apart with the subjects' eyes closed and relaxed. Research tobacco cigarettes smoked were of average (1.0 mg) and low (0.08 mg) nicotine but similar tar yield (9.5 and 9.1 mg). Increases in normalized rCBF were obtained in the occipital cortex, cerebellum, and thalamus, and decreases in the anterior cingulate, nucleus accumbens, amygdala, and hippocampus immediately after smoking the first average nicotine yield cigarette of the morning. After smoking the second average nicotine yield cigarette, the effects were less than smoking the first. Low-nicotine cigarettes produced fewer changes in rCBF than those after the first average cigarette. As expected, statistically significant correlations were found between increases in arterial plasma nicotine and HR. Correlations with arterial nicotine on rCBF were statistically significant in brain areas with the greatest changes in relative blood flow such as the cerebellum and occipital cortex. Nicotine delivery by tobacco smoking is only one of the factors, which contribute to changes in rCBF.

Effects of tobacco smoking on electroencephalographic, auditory evoked and event related potentials

After overnight abstinence, tobacco smokers smoked an average nicotine yield cigarette and nonsmokers sham smoked an unlit placebo cigarette. EEG α 1, δ, and θ frequency amplitudes decreased, whereas α 2 and β frequency amplitude increased. Short, middle (EP) and long latency ERP were also studied in nonsmokers and smokers just after smoking, and after overnight abstinence from tobacco. Short latency potentials were unaffected by tobacco smoking or abstinence. Middle and long-latency potentials were reduced during abstinence and enhanced immediately after tobacco smoking. These findings indicate that compared to nonsmokers smokers have a higher arousal level after smoking than when partially abstinent. Evidence for both normalization from tobacco abstinence as well as stimulation was obtained.

Official cigarette tar tests are misleading: use a two-stage, compensating test

The standard smoking-machine test for cigarettes 1 Peeler CE Cigarette testing and the Federal Trade Commission: a historical overview. in: The FTC cigarette test method for determing tar, nicotine, and carbon monoxide yields of US cigarettes. National Cancer Institute, Bethesda, MD, USA1996: 1-8 Google Scholar has a strong and regrettable power over cigarette sales and public health. The official test determines which cigarettes are called low-tar, light, or ultralight. Such a test establishes which cigarettes meet the European Union (EU) maximum of 12 mg tar, and will confirm compliance with a proposed change in maximum tar to 10 mg and 1·0 mg nicotine (http://europa.eu.int/eur-lex/en/com/pdf/1999/en-599PC0594.pdf accessed on April 11). The promotion of official low-tar cigarettes helps keep health-conscious smokers smoking 2 Kozlowski LT Goldberg ME Yost BA White EL Sweeney CT Pillitteri JL Smokers' misperceptions of light and ultra-light cigarettes may keep them smoking. Am J Prev Med. 1998; 15: 9-16 Summary Full Text Full Text PDF PubMed Scopus (160) Google Scholar , 3 Warner KE Slade J Low tar, high toll. Am J Public Health. 1992; 82: 17-18 Crossref PubMed Scopus (26) Google Scholar and is arguably the cigarette industry's main response to the disease risks of smoking. 4 Glantz SA Slade J Bero LA Hanauer P Barnes DE The cigarette papers. University of California Press, Berkeley and Los Angeles, USA1996 Google Scholar Whether such low-tar cigarettes offer any reduction in risk of death and disability is doubtful. 5 Royal College of PhysiciansNicotine addiction in Britain: a report of the Tobacco Advisory Committee of the Royal College of Physicians. Royal College of Physicians, London2000 Google Scholar , 6 Samet JM The changing cigarette and disease risk: current status of the evidence. in: The FTC Cigarette test method for determining tar, nicotine, and carbon monoxide yields of US Cigarettes. National Cancer Institute, Bethesda, MD, USA1996: 77-92 Google Scholar The smoking-machine procedure (a 35 mL puff of 2 s duration every 60 s) originated in 1936 for manufacturer testing of tobacco blends. 7 Kozlowski LT Physical indicators of actual tar and nicotine yields of cigarettes. National Institute on Drug Abuse, Bethesda, MD, USA1983 Google Scholar At that time, cigarettes were generally 70 mm and unfiltered and all brands were similar to each other. Today, cigarettes vary greatly in length (70–120 mm), width, tobacco blends, and degree of filter ventilation (0% to more than 80% air dilution) 8 Kozlowski LT Mehta NY Sweeney CT et al. Filter ventilation and nicotine content of tobacco in cigarettes from Canada, the United Kingdom, and the United States. Tobacco Control. 1998; 7: 369-375 Crossref PubMed Scopus (136) Google Scholar .

Risk factors associated with the development of peripheral arterial disease in smokers: a case-control study

Purpose and method: A hospital based case-control study was designed to investigate what aspects of smoking and what co-factors of smoking are associated with the development of peripheral arterial disease (PAD). Cases were 291 smokers, newly referred with PAD, and controls were 828 age and sex matched smokers without PAD. Results: Reported recent tobacco usage was similar in cases and controls but total tobacco exposure was associated with the risk of PAD—adjusted odds ratios (ORs) increasing with tertile of pack-years smoked to reach 1.63 (95% CI, 1.11–2.39; P=0.011), for the highest tertile (>48 pack-years) compared with smokers in the lowest tertile (<31 pack-years). Cases reported smoking significantly lower tar and nicotine yield cigarettes than controls, but tended to inhale more deeply, and had significantly higher plasma concentrations of cotinine. ORs for PAD were significantly and independently increased by systolic blood pressure ≥160 mmHg (8.1 (5.2–13.0); P<0.0001), history of hypertension (2.4 (1.5–3.2); P=0.0003) and apolipoprotein B>0.9 g/l(3.8 (2.3–7.6); P=0.008). Conclusions: Increased total exposure to tobacco and the ability to smoke tobacco in a way which maximises nicotine yield are associated with increased risk of smokers developing PAD. There is no evidence that smoking low tar cigarettes reduces this risk, whereas both hypertension (particularly systolic) and high levels of apolipoprotein B, increase this risk.

Smoking multiple high- versus low-nicotine cigarettes: Impact on resting energy expenditure

The thermic effect of smoking multiple cigarettes varying substantially in nicotine yield was investigated. Three treatments were imposed: nonsmoking at baseline, smoking six low-nicotine (0.8 mg nicotine) cigarettes (LOW), and smoking six high-nicotine (1.74 mg nicotine) cigarettes (HIGH). An initial increase of 6.8% in resting energy expenditure (REE) above baseline REE occurred after consumption of two consecutive cigarettes for both the HIGH and LOW treatments. With consumption of more cigarettes, the peak increase for the HIGH treatment was 9.3%, significantly greater than the peak of 5.9% for the LOW. Averaged over 2 hours, the HIGH treatment significantly increased REE by 6.9% and the LOW treatment significantly increased REE by 5.2%. Expired carbon monoxide (CO) measurements indicated that LOW cigarettes were smoked more aggressively than HIGH cigarettes. It was concluded that, initially, the nicotine yield of cigarettes is not an important influence on the thermic effect of smoking. But over a longer period and after multiple cigarettes, the nicotine yield may become an important influential factor.

Faster P300 latency after smoking in visual but not auditory oddball tasks.

In two separate experiments, P300 was recorded from overnight-abstaining smokers before and after smoking. In the first experiment, 32 subjects counted forward by ones and counted backwards by threes upon presentation of a rare tone burst (20%) in a stream of standard tones. There were no changes in P300 amplitude or latency pre- to post-smoking (1.1-mg FTC nicotine-yield cigarette). In the second experiment, 29 subjects completed auditory and visual oddball tasks before smoking, after smoking a low nicotine-yield cigarette (0.05 mg), after smoking a higher nicotine-yield cigarette (1.1-mg), and after smoking a second 1.1-mg cigarette. In the visual oddball task, P300 latency decreased after smoking the first higher-yield cigarette relative to both pre-smoking and post smoking the lower-yield cigarette. This effect was maintained after smoking the second higher-yield cigarette. In the visual task, P300 amplitude increased after smoking the first higher-yield cigarette (from a lower baseline level) in a group of subjects with larger changes in tidal-breath CO but not in a group with smaller changes in CO. There were no effects of smoking on P300 amplitude or latency in the auditory tasks of either the first or second experiment.

Human Smoking Behaviour in Comparison with Machine Smoking Methods: A Summary of the Five Papers Presented at the 1995 Meeting of the CORESTA Smoke and Technology Groups in Vienna

Abstract During the last months there have been extensive discussions, particularly in the United States, whether and to what extent data obtained by machine smoking using standardized methods (e.g. ISO, FTC, Coresta) permit conclusions about the actual uptake of smoke constituents (nicotine, condensate, etc.) by a smoker. This topic was a major focus of interest at the meeting of the Coresta Smoke and Technology Group in Vienna from 10th to 14th September 1995. A total of five studies were presented, four of which compared smoke yields obtained by standard machine smoking with actual yields obtained by human smoking. The fifth study investigated the effect of alternative puffing regimens and filter vent blocking on “tar” and nicotine yields of cigarettes. This paper summarizes the essential findings of the five studies.

Effects of smoking abstinence and chain-smoking on puffing topography and diurnal nicotine exposure

Effects of chain-smoking, a 15-h smoking abstinence, and the nicotine yield of cigarettes on puff indices were studied in eight healthy smokers by using a controlled crossover study design. Puff parameters were measured puff by puff with a portable measuring device when 10 or 20 cigarettes, with nicotine yields of 0.3 and 1.0 mg, were smoked per day. The interval between sessions was 1 h, and the 20 cigarettes per day were chain-smoked 2 at a time. Serum cotinine indicated that smokers compensate completely for the lower nicotine delivery from the 0.3-mg cigarette. Smokers almost doubled total puff volume per cigarette and per day mainly by taking more puffs from the low-nicotine cigarettes and slightly prolonging puff duration. However, nicotine deprivation and chain-smoking had a relatively minor effect on puffing indices with both brands, a fact that agrees poorly with the nicotine titration hypothesis. However, in the course of every single cigarette of the day smokers significantly reduced puff duration and puff volume toward the end of the cigarette, which probably involves satiation of the nicotine crave but may also be due to changes in taste of the smoke.

Effects of spirometric administration of tobacco smoke containing varying amounts of nicotine on human punished and non-punished operant responding

Lever pulling of male tobacco smokers was maintained by a variable interval 20sec schedule (VI 20) of point presentation. In experiment 1 the rate of lever pulling was suppressed by a punishment contingency which stipulated that lever pulls would produce point subtractions on a variable ratio 30 schedule (VR 30). In experiment 2 the punishment contingency was omitted. Each subject participated in eight sessions each day (Mon. through Fri.). Each block of two 20-min sessions was separated by a period during which tobacco smoke containing varying amounts of nicotine was administered by the spirometry method, which ensured a constant puff volume and deep inhalation. The tobacco smoke conditions were: (1) 0.3mg nicotine yield cigarettes (baseline condition), (2) 1.2mg nicotine yield cigarettes, (3) 2.7mg nicotine yield cigarettes and (4) a condition in which room-temperature air was administered. Subjects remained at baseline conditions until responding stabilized and were then exposed to higher nicotine yield smoke or air for an entire day. Subjects were then returned to baseline conditions before administration of higher nicotine yield smoke or air. In experiment 1 (punishment contingency) lever pulling decreased as a function of increasing nicotine content in tobacco smoke. This effect upon responding was similar to the effects of CNS stimulants on punished responding in non-human subjects. In experiment 2 (no punishment contingency), no consistent effect of tobacco smoke or non-punished responding was observed.