The effect of acute cigarette smoke inhalation on pulmonary and systemic cysteine and glutathione redox states in the rat

Determination of oxidative stress level and some antioxidant activities in refractory epilepsy patients

The aim of this study was to determine the levels of superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and malondialdehyde (MDA) in patients with refractory epilepsy. Serum superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and malondialdehyde (MDA) levels were determined using the spectrophotometer method. Refractory epilepsy patients' serum superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and malondialdehyde (MDA) levels were statistically significant compared to the healthy control group (p < 0.05). In conclusion, superoxide dismutase (SOD), catalase (CAT), reduced glutathione (GSH) and malondialdehyde (MDA) levels may play an important role in the etiopathogenesis of refractory epilepsy. This study was the first to investigate some parameters in refractory epilepsy disease.

Ameliorating effects of Nigella sativa oil on aggravation of inflammation, oxidative stress and cytotoxicity induced by smokeless tobacco extract in an allergic asthma model in Wistar rats

BACKGROUND

The comparison of smokeless tobacco (ST) exposure versus Ovalbumin (Ova) sensitized rats or asthmatic patients has hardly been studied in the literature. Thus, the present study aims to investigate the aggravation of inflammation, exacerbation of asthma, oxidative stress and cytotoxicity induced by ST.

METHODS

ST was given at the dose of 40mg/kg in an allergic asthma model in Wistar rats. Furthermore, the effects of oral administration of Nigella sativa oil (NSO), at a dose of 4mL/kg/day, were investigated.

RESULTS

The obtained results showed that ST clearly enhanced lung inflammation through interleukin-4 (IL-4) and Nitric oxide (NO) increased production. Actually, ST was found to intensify the oxidative stress state induced by Ova-challenge in rats, which was proven not only by augmenting lipid peroxidation and protein oxidation, but also by altering the non-enzymatic and enzymatic antioxidant status. Furthermore, the aggravation of inflammation and oxidative stress was obviously demonstrated by the histopathological changes observed in lung. In contrast, NSO administration has shown anti-inflammatory effects by reducing IL-4 and NO production, restoring the antioxidant status, reducing lipid peroxidation and improving the histopathological alterations by both protein oxidation and NSO treatment.

CONCLUSIONS

Our data have proven that severe concurrent exposure to allergen and ST increases airway inflammation and oxidative stress in previously sensitized rats. They also suggest that the oral NSO treatment could be a promising treatment for asthma.

Acute exposure to waterpipe tobacco smoke induces changes in the oxidative and inflammatory markers in mouse lung

CONTEXT

Tobacco smoking represents a global public health threat, claiming approximately 5 million lives a year. Waterpipe tobacco use has become popular particularly among youth in the past decade, buttressed by the perception that the waterpipe "filters" the smoke, rendering it less harmful than cigarette smoke.

OBJECTIVE

In this study, we examined the acute exposure of waterpipe smoking on lung inflammation and oxidative stress in mice, and compared that to cigarette smoking.

MATERIALS AND METHODS

Mice were divided into three groups; fresh air control, cigarette and waterpipe. Animals were exposed to fresh air, cigarette, or waterpipe smoke using whole body exposure system one hour daily for 7 days.

RESULTS

Both cigarette and waterpipe smoke exposure resulted in elevation of total white blood cell count, as well as absolute count of neutrophils, macrophages, and lymphocytes (P < 0.01). Both exposures also elevated proinflammatory markers such as TNF-α and IL-6 in BALF (P < 0.05), and oxidative stress markers including GPx activity in lungs (P < 0.05). Moreover, waterpipe smoke increased catalase activity in the lung (P < 0.05). However, none of the treatments altered IL-10 levels.

DISCUSSION AND CONCLUSION

Results of cigarette smoking confirmed previous finding. Waterpipe results indicate that, similar to cigarettes, exposure to waterpipe tobacco smoke is harmful to the lungs.

The alteration of protein profile induced by cigarette smoking via oxidative stress in mice epididymis

Smoking is associated with a declining quality of semen. The aim of this study was to screen and investigate the differential expression of proteins extracted from the epididymis of mice exposed daily with cigarette smoke. Using MALDI-TOF-MS analysis, we found that the protein profile of the mouse epididymis was altered by cigarette smoking and identified 27 proteins from the most abundant and differentially expressed spots in the 2-DE gels of epididymal samples. These proteins were classified into groups according to their functions such as energy metabolism, reproduction and structural molecule activity. Through pathway analysis, these proteins were associated with the glutathione metabolism and protein processing in the endoplasmic reticulum. These results showed that the epididymis may experience oxidative stress following cigarette smoke exposure, which was confirmed using immunohistochemistry. We determine that cigarette smoking can induce oxidative stress in the mouse epididymis, which may cause protein profile altering, thereby impairing epididymis function, and leading to a decline in semen quality.

Evaluation of the pulmonary effects of short-term nose-only cigarette smoke exposure in mice

Much is known about the chronic effects of cigarette smoke (CS) on lung function and inflammation and development of chronic obstructive pulmonary disease. However, the underlying pathophysiological mechanisms related to the short-term exposure to CS are not fully understood. Here, we assessed the effect of CS generated by nine consecutive cigarettes per day for four days in a nose-only exposure system on airway resistance measured using forced oscillation technique, lung inflammation and oxidative stress in BALB/c mice. Control mice were exposed to air. Mice exposed to CS showed a significant increase of neutrophils and lymphocytes numbers in bronchoalveolar lavage (BAL). The total protein and endothelin levels in BAL fluid were significantly augmented suggesting an increase of alveolar-capillary barrier permeability. Similarly, airway resistance was significantly increased in the CS group compared with controls. Furthermore, reactive oxygen species and lipid peroxidation levels in lung tissue were significantly increased. The antioxidant activities of reduced glutathione, glutathione S transferase and superoxide dismutase were all significantly increased following CS exposure, indicating that CS could trigger adaptive responses that counterbalance the potentially damaging activity of oxygen radicals induced by CS exposure. In conclusion, our data indicate that short-term nose-only exposure to CS causes lung inflammation and increase of airway resistance mediated at least partly through the oxidative stress.

Mycoplasma pneumoniae infection and environmental tobacco smoke inhibit lung glutathione adaptive responses and increase oxidative stress

Chronic cigarette smoking evokes a lung glutathione (GSH) adaptive response that results in elevated GSH levels in the lung epithelial lining fluid (ELF). Currently, little is known about how the lung regulates or maintains steady-state levels of ELF GSH. Pathogens such as Mycoplasma pneumoniae can exacerbate airway inflammation and oxidative stress. The present study examined whether M. pneumoniae infections synergize with environmental tobacco smoke (ETS) to disrupt lung GSH adaptive responses. Mice were exposed separately and in combination to ETS and M. pneumoniae for 16 weeks. ETS exposure resulted in a doubling of ELF GSH levels, which was blocked in the M. pneumoniae-exposed mice. In addition, the ETS-plus-M. pneumoniae-exposed mice had elevated levels of oxidized glutathione (GSSG), resulting in a dramatic change in the ELF redox state that corresponded with an increase in lung tissue DNA oxidation. Similar findings were observed in human lung epithelial cells in vitro. Cells exposed separately or in combination to cigarette smoke extract and M. pneumoniae for 48 h had elevated apical levels of GSH compared to control cells, and these increases were blocked by M. pneumoniae and were also associated with increased cellular DNA oxidation. Further studies showed that M. pneumoniae exposure blocked ETS-induced increases in GSH reductase, an enzyme that recycles GSSG back to GSH, both in vitro and in vivo. These studies suggest that M. pneumoniae infection synergizes with ETS and suppresses the lung's ability to respond appropriately to environmental challenges leading to enhanced oxidative stress.

Cigarette smoke irreversibly modifies glutathione in airway epithelial cells

In patients with chronic obstructive pulmonary disease (COPD), an imbalance between oxidants and antioxidants is acknowledged to result in disease development and progression. Cigarette smoke (CS) is known to deplete total glutathione (GSH + GSSG) in the airways. We hypothesized that components in the gaseous phase of CS may irreversibly react with GSH to form GSH derivatives that cannot be reduced (GSX), thereby causing this depletion. To understand this phenomenon, we investigated the effect of CS on GSH metabolism and identified the actual GSX compounds. CS and H(2)O(2) (control) deplete reduced GSH in solution [Delta = -54.1 +/- 1.7 microM (P < 0.01) and -39.8 +/- 0.9 microM (P < 0.01), respectively]. However, a significant decrease of GSH + GSSG was observed after CS (Delta = -75.1 +/- 7.6 microM, P < 0.01), but not after H(2)O(2). Exposure of A549 cells and primary bronchial epithelial cells to CS decreased free sulfhydryl (-SH) groups (Delta = -64.2 +/- 14.6 microM/mg protein, P < 0.05) and irreversibly modified GSH + GSSG (Delta = -17.7 +/- 1.9 microM, P < 0.01) compared with nonexposed cells or H(2)O(2) control. Mass spectrometry (MS) showed that GSH was modified to glutathione-aldehyde derivatives. Further MS identification showed that GSH was bound to acrolein and crotonaldehyde and another, yet to be identified, structure. Our data show that CS does not oxidize GSH to GSSG but, rather, reacts to nonreducible glutathione-aldehyde derivatives, thereby depleting the total available GSH pool.

Systemic effects of cigarette smoke exposure in the guinea pig

Chronic obstructive pulmonary disease is associated with systemic effects including reduced body weight, oxidative stress and altered circulating TNFalpha levels. The present study was aimed to investigate whether chronic exposure to cigarette smoke induces these systemic changes in a guinea pig model. Seven animals/group were exposed to the smoke of seven cigarettes/day, 5 days/week, during 2, 4 and 6 months (chronic exposure). Three animals/group were sacrificed immediately, 3 h or 24 h after exposure to seven cigarettes (acute exposure). Chronically smoke-exposed animals exhibited lower body weight gain, starting at 5th week, and goblet cell metaplasia in small bronchioles. At 6 months there was a trend for increased plasma and lung tissue TNFalpha levels. No changes, neither in skeletal muscle glutathione (GSH) nor in plasma lipid peroxidation, were observed at any time point after chronic exposure. However, skeletal muscle GSH decreased and plasma lipid peroxidation increased immediately after acute smoke exposure, equaling control levels thereafter. We conclude that cigarette smoke exposure in the guinea pig induces a transient and repeated oxidative effect, which might result in impaired systemic metabolism and consequent failure of smoke-exposed animals to gain weight. The effects of cigarette smoke on body weight antecede and appear to be independent from the alterations produced in small airways.

Smokeless tobacco impairs the antioxidant defense in liver, lung, and kidney of rats

The present study was designed to evaluate the effects of long-term use of aqueous extract of gutkha (a form of smokeless tobacco) on the antioxidant defense status and histopathological changes in liver, lung, and kidney of male Wistar rats. Animals were orally administered aqueous extract of smokeless tobacco (AEST) at a low dose (96 mg/kg body weight per day) for 2 and 32 weeks, and at a high dose (960 mg/kg body weight per day) for 2 weeks. High-dose AEST for 2 weeks decreased the hepatic glutathione (GSH) and glutathione peroxidase (GPx), and increased lipid peroxidation (Lpx) by 17%, 19%, and 20%, respectively. Low-dose AEST for 32 weeks significantly decreased (p < 0.05) the antioxidant status in these organs. In liver, AEST decreased GSH levels and the activities of superoxide dismutase (SOD), catalase (CAT), and GPx by 34.6%, 29%, 17.1%, and 17.4%, respectively, but it increased Lpx by 64%. In kidney, GSH, SOD, CAT, and GPx were decreased by 26.6%, 23%, 33%, and 18%, respectively, with an increase of Lpx by 65%. AEST decreased the lung GSH, SOD, CAT, and GPx, and increased lung Lpx by 43%, 28.5%, 37%, 40%, and 24%, respectively. However, no change in the plasma levels of vitamins A, C, and E were observed with AEST treatment. Histopathological findings suggest that administration of AEST at the high dose for 2 weeks or at the low dose for 32 weeks could cause mild to moderate inflammation in liver and lungs. In conclusion, a decrease in the antioxidant defense system and long-term inflammation caused by smokeless tobacco may be risk factors for gutkha-induced pathogenesis.

Acute effects of cigarette smoke on inflammation and oxidative stress: a review

Compared with the effects of chronic smoke exposure on lung function and airway inflammation, there are few data on the acute effects of smoking. A review of the literature identified 123 studies investigating the acute effects of cigarette smoking on inflammation and oxidative stress in human, animal, and in vitro models. An acute smoking model is a relatively easy and sensitive method of investigating the specific effects of cigarette smoke on oxidative stress and inflammation. Acute smoke exposure can result in tissue damage, as suggested by increased products of lipid peroxidation and degradation products of extracellular matrix proteins. Acute cigarette smoke has a suppressive effect on the number of eosinophils and several inflammatory cytokines, possibly due to the anti-inflammatory effect of carbon monoxide. An acute smoking model can supplement other ways of studying the effects of smoking and is an as yet underinvestigated method for intervention studies in smoking related diseases.

Oxidant injury, nitric oxide and pulmonary vascular function: implications for the exercising horse

The athletic ability of the horse is facilitated by vital physiological adaptations to high-intensity exercise, including a thin (but strong) pulmonary blood-gas barrier, a large pulmonary functional reserve capacity and a consequent maximum oxygen uptake (VO2max) far higher than in other species. A high pulmonary artery pressure also serves to enhance pulmonary function, although stress failure of lung capillaries at high pulmonary transmural pressures, and the contribution of other factors which act in the exercising horse to increase pulmonary vascular tone, may lead to pathological or pathophysiological sequelae, such as exercise-induced pulmonary haemorrhage (EIPH). Reactive oxygen species (ROS) are an important component of the mammalian inflammatory response. They are released during tissue injury and form a necessary component of cellular defences against pathogens and disease processes. The effects of ROS are normally limited or neutralized by a multifactorial system of antioxidant defences, although excessive production and/or deficient antioxidant defences may expose healthy tissue to oxidant damage. In the lung, ROS can damage pulmonary structures both directly and by initiating the release of other inflammatory mediators, including proteases and eicosanoids. Vascular endothelial cells are particularly susceptible to ROS-induced oxidant injury in the lung, and both the destruction of the pulmonary blood-gas barrier and the action of vasoactive substances will increase pulmonary vascular resistance. Moreover, ROS can degrade endothelium-derived nitric oxide (NO), a major pulmonary vasodilator, thereby, with exercise, synergistically increasing the likelihood of stress failure of pulmonary capillaries, a contributing factor to EIPH. This review considers the implications for the exercising horse of oxidant injury, pulmonary vascular function and NO and the contribution of these factors to the pathogenesis of equine respiratory diseases.

Immunological changes produced in rats by prenatal exposure to carbon monoxide

Wistar female rats were exposed to relatively mild concentrations of carbon monoxide (CO) (75 and 150 p.p.m.) from day 0 to day 20 of pregnancy. The results show that splenic macrophage phagocytosis of Candida albicans was significantly decreased in 15 and 21 day old male rats exposed to CO (150 p.p.m.) during pregnancy. Moreover, splenic macrophage killing was significantly reduced in 15 day old male pups prenatally exposed to 75 and 150 ppm of CO. Prenatal CO (150 p.p.m.) significantly decreased splenic macrophage O2- release in both 15 and 21 day old pups. CO-induced alterations in the immune system were not observed in 60 day old rats. These findings indicate that gestational exposure to relatively mild concentrations of CO induces in rat offspring reversible immunological changes characterized by an altered splenic macrophage function.

Comparison of antioxidant substances in bronchoalveolar lavage cells and fluid from humans, guinea pigs, and rats

Antioxidants located in the lining layer of the respiratory tract may be important in determining sensitivity of lung tissues to inhaled pollutants. This study addressed species differences in the amounts of ascorbic acid (AH2), glutathione (GSH), uric acid (UA), and alpha-tocopherol (AT) in bronchoalveolar lavage (BAL) fluid and cells of humans, guinea pigs, and rats. Protein and lipid phosphorus (lipid P) were used as normalizing factors. More than 90% of the lavageable AH2, UA, GSH, protein, and lipid P was present in the extracellular fraction of BAL in rats and guinea pigs, while over 95% of the lavageable AT was located in the BAL cells. BAL fluid AH2/protein in rats was 7- to 9-fold higher than in humans and guinea pigs. However, human BAL fluid had 2- to 8-fold higher UA/protein, GSH/protein, and AT/protein ratios than rats and guinea pigs. In BAL cells, rats had higher AH2/protein and AT/protein ratios than guinea pigs and humans, and both rats and guinea pigs had higher GSH and AT/protein ratios than humans. Individual variability among humans in the BAL fluid and cellular antioxidants was generally greater than in the laboratory animals. These data demonstrate that some large species differences exist in BAL fluid and cellular antioxidants which could affect susceptibility to oxidant pollutants.

Cigarette smoking and oxidative damage in the lung

Cigarette smoke contains a large variety of compounds, including many oxidants and free radicals that are capable of initiating or promotes oxidative damage. Also, oxidative damage may result from reactive oxygen species generated by the increased and activated phagocytes following cigarette smoking. In vitro studies are generally supportive of the hypothesis that cigarette smoke can initiate or promote oxidative damage. However, information obtained from in vivo studies is inconclusive. Contrary to expectations, the levels of lipid peroxidation products were found to be decreased or unchanged in the lungs of chronically smoked rats. Metabolic adaptation, such as accumulation of vitamin E in the lung, and increased activities of superoxide dismutase in alveolar macrophages and pulmonary tissues of chronically smoked animals may enable smoked subjects to counteract oxidative stress and to resist further damage to smoke exposure. However, it is also possible that the metabolic adaptation may be secondary to inflammatory response and injury repair process following smoking exposure. More studies are needed to better understand the role of oxidative damage in the etiology of smoking-related disorders.

Changes in neutrophil deformability following in vitro smoke exposure: mechanism and protection

We have previously demonstrated a reduction in the deformability of neutrophils, exposed to whole particulate cigarette smoke in vitro, by measuring their ability to filter through a micropore membrane with pore dimensions similar to those of the average pulmonary capillary segment. In this study, we exposed neutrophils to the vapor phase of cigarette smoke and investigated the mechanism of the reduction in neutrophil filterability. Although both stimulated neutrophils and smoke-exposed neutrophils demonstrated an increase in filtration pressures, and thus a reduction in cell deformability, compared with control untreated cells, the spontaneous release of the reactive oxygen intermediates hydrogen peroxide and the superoxide anion was depressed following in vitro smoke exposure and there was no shape change to suggest that smoke-exposed cells were activated. The presence of erythrocytes, plasma, or the antioxidants albumin and glutathione prevented the reduction in cell filterability following smoke exposure, suggesting that in vitro smoke exposure, in our system, was mediated by oxidants. Indeed, the increase in filtration pressures, produced by smoke, could be mimicked by the addition of the oxidant hypochlorous acid. The cytoskeletal inhibitors cytochalasin B and D improved the filterability of smoke-exposed cells, suggesting that smoke may change neutrophil deformability through an effect on the actin component of the cytoskeleton. By contrast, colchicine, a specific inhibitor of the microtubules, had no effect. Preincubation with a monoclonal antibody to the CD18 antigen, to block this major neutrophil adhesive glycoprotein, did not alter the filtration pressure developed by stimulated or smoke-exposed neutrophils, suggesting that increased adhesivity was not the mechanism of the increase in filtration pressures observed following smoke exposure.(ABSTRACT TRUNCATED AT 250 WORDS)

Protective antioxidant mechanisms in rat and guinea pig tissues challenged by acute exposure to cigarette smoke

Cellular damage from reactive intermediates formed during xenobiotic biotransformation is prevented by the presence of adequate levels of antioxidant chemicals in the tissues. Equally important for cell protection is the rate at which these chemicals are replaced if tissue stores are depleted. The present experiments, using adult male Sprague-Dawley rats and Hartley guinea pigs, were conducted to ascertain what effects mainstream (MS) and sidestream (SS) tobacco smoke would have on the water-soluble, cytoplasmic antioxidants, ascorbic acid (AA) and reduced glutathione (GSH). The animals were exposed by nose-only inhalation to varying doses (40, 120, 240 puffs) of a 1:5 dilution of a 35-ml volume of freshly generated MS from cigarettes made from different types of tobacco and delivered by a B.-A.T-Mason inhalation apparatus. The animals were euthanized either immediately following exposure or at 3 and 6 h. The blood, lungs, liver, kidneys, heart and bladder were removed for the quantitation of AA and GSH following homogenization and deproteinization. Immediately following exposure to MS, dose-dependent decreases in pulmonary and renal GSH were observed in rats whereas, in guinea pigs, reductions in pulmonary, hepatic and renal GSH were observed only at the highest level of exposure. No reductions in tissue AA were observed in either species at any exposure level. In both species, blood levels of GSH and AA remained unchanged following exposure. Mainstream smoke (240 puffs) from flue-cured or dark, air-cured tobaccos elicited a significant, immediate reduction in pulmonary and renal GSH, but MS from low tar, filter cigarettes was without effect. Within 3 h of exposure, GSH in all tissues has returned to pre-exposure levels. Whole-body, chamber exposure to concentrated SS, generated from smouldering cigarettes, caused a dose-dependent reduction in rat pulmonary, hepatic, renal, cardiac and bladder muscle GSH but only affected pulmonary GSH in the guinea pig. Lesser effects were observed in tissues of rats exposed to diluted SS. In the rat, a comparison of the results of diethylmaleate- and smoke-induced depletion of tissue GSH suggested that, even at exceptionally high levels of exposure, there was a significant store of GSH in tissues that did not interact with tobacco smoke.

Lung and systemic thiol homeostasis during an acute lung inflammation in the rat

The instillation of Sephadex beads into the lungs of rats induces a sustained, acute inflammatory reaction within the lungs which caused significant increases in whole lung free and total glutathione (GSH) of approximately 30% after 72 h of reaction. Concurrently, levels of free and total cysteine (CySH) were increased by approximately 600% and 300%, respectively. Similarly, extended inflammation raised the intracellular content of free and total GSH in intraluminal cells by approximately 50% whilst causing the accumulation of oxidised CySH in the extracellular lavage fluid. Simultaneously, fluctuative trends were noted in several systemic thiol pools. Liver free and total GSH were shown to fall without alteration to CySH components. In contrast the plasma redox balance of GSH was unaltered but depletions of free and total CySH were noted after 72 h of inflammation. These results are discussed in terms of the occurrence of oxidative stress during acute pulmonary inflammation and the relationship of these observations to systemic thiol homeostasis and observations in other models of oxidant-induced pulmonary toxicity.

The anti-inflammatory activity of Ebselen but not thiols in experimental alveolitis and bronchiolitis

This paper describes the effects of the thiol compounds glutathione and N-acetylcysteine and the seleno-organic agent Ebselen on the development of Sephadex-induced lung edema and cell infiltration in the rat. Neither thiol had any effect upon the development of the edema when administered in large, repeated doses. In contrast, when Ebselen was co-administered with the thiols, there was a dose-dependent inhibition of the development of the edema, but lung weights could not be returned to normal values. However, when the thiols were omitted and Ebselen was administered alone, the development of the edema was totally blocked. In addition, in Ebselen-only treated animals there was a selective inhibition of the infiltration of lymphocytes, basophils and eosinophils into the lung lumen without affecting the populations of macrophages and neutrophils. Again, the Ebselen-induced effect was reduced by coadministration of either thiol. These findings are discussed in terms of the potential mechanism of action of Ebselen in vivo and of the possibility of Ebselen being of therapeutic potential in cases of diffuse pulmonary inflammation in humans.

Hydroperoxide and cigarette smoke induced effects on lung mechanics and glutathione status in rat isolated perfused and ventilated lungs

The effects of t-butylhydroperoxide (TBH) and cigarette smoke on lung mechanics (CDYN and RL) and glutathione status (GSH) were studied using an isolated perfused and ventilated rat lung preparation. TBH (200, 400, 1000 microM) infused via the pulmonary circulation caused a dose-related bronchoconstriction. The lung GSH-levels were also significantly reduced. Pretreatment of rats with diethylmaleate (DEM) potentiated the TBH elicited bronchoconstriction. DEM (1 mM) infused into the pulmonary circulation caused an almost complete depletion of GSH-content but no effects on lung mechanics were seen. Indomethacin (2.8 and 28 microM) infusion attenuated TBH (400 microM) induced bronchoconstriction. These findings suggest that the TBH induced bronchoconstriction is at least partly mediated via arachidonic acid metabolites. When TBH was administered intratracheally, weak and not dose-related bronchoconstriction was observed even though doses higher than those given intravascularly were used. However, the GSH-content of the lungs was markedly decreased. Cigarette smoke caused weak if any effects on lung mechanics but significantly decreased lung GSH-content.