Institute For Science And Health

Tobacco Science and Health Program Initiative - Projects from RFA 2003-A

Prenatal Exposure to Cigarette Smoke and Chronic Airway Disease in the Offspring: Toxicological impact of the Particulate and Vapor Phase

Dr. Judith T. Zelikoff

New York University School of Medicine, Dept. of Environmental Medicine, Tuxedo, NY

Final Report (Last Updated – December 2007)

Epidemiologic and toxicologic data indicate that smoking during pregnancy increases the risk of offspring respiratory ailments (e.g., asthma) later in life. While these findings carry extensive clinical consequences, little data are available to provide insight into the possible mechanisms by which these effects might occur. We hypothesize that inhalation exposure to mainstream cigarette smoke (MCS) by pregnant mice influences immune-mediated airway reactivity in the offspring. Pregnant CD1 mice were exposed daily for 4 hr/d (5 d/wk) from gestational day 4 to parturition to intact MCS at a concentration equivalent to smoking <1 pack of cigarettes per day. Changes in airway reactivity were evaluated in naove or ovalbumin (OVA)-sensitized, prenatally exposed offspring by a non-specific bronchoprovocation challenge with acetylcholine (Ach) at 5 or 8 and 15 or 18 wk of age, depending upon the protocol; immune parameters known to mediate airway reactivity were also evaluated. In the absence of effects on pregnancy incidence, gestational duration, litter size or offspring sex ratio, prenatal exposure to MCS enhanced airway reactivity and elevated plasma IgE concentrations (compared to the sex/age-matched, air exposed controls) in 5-wk-old naove female (but, not male) offspring. In contrast, airways of prenatally exposed 4-mo-old naove female offspring were significantly less responsive to Ach challenge than their matched controls. OVA-sensitized offspring exposed prenatally to MCS tended to have higher plasma IgE levels than their age-matched, air-exposed controls; sensitized 18-wk-old male offspring were more sensitive to Ach challenge than their age- and treatment-matched female counterparts. Results suggest that prenatal exposure to CS: affects airway health in a gender-dependent manner; increases offspring allergic antibody levels and airway reactivity; may play a role in the induction and/or exacerbation of allergy-related outcomes; and, has long-term effects on offspring respiratory health and may increase the risk of respiratory dysfunction later in life.

Biomonitoring of Tobacco Smoke-related Aromatic Amines in Smokers versus Non-smokers

Dr. Albrecht Seidel

Biochemical Institute for Environmental Carcinogens, Prof. Dr. Gernot Grimmer-Foundation, Grosshansdorf , Germany

Final Report (Last Updated – December 2007)

Several aromatic amines (AA) have been identified as bladder carcinogens and may account for the positive correlation between cigarette smoking and the incidence of bladder cancer in humans. However, only about 50% of attributed risk for bladder cancer is associated with cigarette smoking, which seems to indicate that there remains some exposure to AA that is not associated with tobacco smoke.

In this cross-sectional study 140 participants will be investigated including 120 non-smokers and 20 smokers. The study is aimed at (i) identifying potential sources of exposure of AA for non-smokers by means of questionnaire, (ii) investigating the relationship between excreted AA levels in urine and hemoglobin(Hb) adduct levels, and (iii) demonstrating a possible association between CYP1A2 phenotype, NAT1, NAT2 or GSTM1 genotypes and excreted AA levels in urine and Hb adduct levels in blood.

Data from 53 non-smoking participants ( 16 men and 37 women ) have been documented and from each individual a 24 hrs-urine as well as a blood sample (to prepare hemoglobin and DNA) have been collected. A protocol of food consumption and beverages covers the time span 24 hrs before urine collection. All participants agreed to take part in a caffeine test for CYP1A2 phenotyping.

At present the profile of AA has been determined in 45 samples. The o-, m- and p-toluidines have been detected in 15, 10, and 8 samples in a range of 0.12-204 µg/L, 1.79-286 µg/L and 0.19-434 µg/L, respectively. 2-Amino- and 4-aminobiphenyl have been found in 41 and 16 samples in a range of 0.05-56 µg/L and 0.04-29 µg/L, respectively, whereas 3-aminobiphenyl concentrations were less than LOQ in all samples.

In parallel the determination of AA hemoglobin adducts and genotyping of each individual for NAT and GST is underway.

Determination of aromatic amine levels in urine specimens
Determination of aromatic amine
Hb adducts in blood specimens
Role of pheno- and genotype of specific human enzymes?
Descriptive and multivariate analysis.

Size Segregated Chemical Composition of Tobacco Aerosol from Regular Cigarettes and Potentially Reduced Exposure Products (PREPs)

Dr. Derek Dunn-Rankin

University of California at Irvine , Irvine , CA

Final Report (Last updated - June 2007)

Potentially Reduced Exposure Products (PREPs) are designed to reduce the health risk associated with cigarette smoking. For this purpose, PREPs utilize modification in tobacco and cigarette design. However, a low nicotine PREP may change the puffing behavior of smokers to achieve nicotine levels comparable to standard cigarettes. Changes in combustion behavior, puffing conditions, composition, and design of cigarettes can alter the characteristics of the smoke and the amount of gases produced. Gases such as carbon monoxide and nitrogen oxides in cigarette smoke have been associated with cardiac and respiratory health problems in smokers. In this work, we have analyzed the gaseous phase for carbon monoxide and nitrogen oxides of a research cigarette (2R4F), a commercial cigarette (Marlboro Medium) and a PREP (Quest1). We have measured these gases using three puffing regimens (1) FTC 35 ml over 2 seconds, (2) short puff 50 ml over 2 seconds, and (3) long puff 100 ml over 10 seconds. Carbon monoxide was measured using an IR gas analyzer and nitrogen oxides (NO and NO 2 ) were measured using a chemiluminescence gas analyzer. The results showed that more gases were produced using short puffing and long puffing regimens than with the FTC puffing regimen for 2R4F and Marlboro cigarettes. However, Quest1 displayed little effect of puffing variation on gases produced (though more NO 2 was produced in the short puffing than in long puffing and FTC puffing regimens). For estimating the dose of nicotine in the respiratory tract, we measure the nicotine content in size-segregated samples of particulate matter of mainstream smoke from these cigarettes. Since particle size distribution of mainstream smoke aerosol control the deposition behavior of particles in the respiratory tract, a relationship between particle size and chemical composition of nicotine can help in its dose assessment.

Role of Reactive Oxygen Species and Cyclooxygenase-2 in Tobacco Smoke-induced Inflammation and Epithelial Damage

Dr. Kevin R. Smith

University of California at Davis, Davis , CA

Final Report (Last Updated – December 2007)

Cigarette smoking is associated with pulmonary inflammation, epithelial damage, and remodeling of the airways resulting in chronic obstructive pulmonary disease (COPD). Chronic airway inflammation plays a key role in the development and progression of tobacco smoke-induced lung disease. However, the molecular mechanisms responsible for changes leading to COPD are as yet undetermined. We have previously demonstrated exposure of spontaneously hypertensive (SH) rats to tobacco smoke results in a striking degree of early pulmonary inflammation persisting throughout multiple weeks of exposure. Exuberant mucous cell hyperplasia is also present. Continued exposure results in further epithelial airway hyperplasia, and some alveolar distension within centriacinar sites of the lung parenchyma, suggestive of centrilobular emphysema. These features are typical of changes in the lungs of human smokers with COPD. Reactive oxygen species, present in tobacco smoke, are known to activate transcription factors, resulting in the synthesis of inflammatory mediators which play a critical role in the initiation and progression of inflammation. We have previously demonstrated that repeated exposure of SH rats to tobacco smoke is associated with up-regulation of the inflammatory mediator cyclooxygenase-2 (COX-2) in the lungs. Use of the SH rat in a model of smoke-induced pulmonary changes affords us the unique opportunity to elucidate more precisely those molecular, cellular, and pathological processes involved in smoke-induced lung disease. During this one-year pilot study we will test the hypothesis that reactive oxygen species in tobacco smoke induce over-expression of COX-2 leading to elevated inflammation and remodeling of the airway epithelium. We hypothesize that these events can be blocked by antioxidants or inhibitors specific for COX-2. Changes will be measured using histopathologic, morphometric, and biochemical techniques.