N-acetylcysteine prevents cigarette smoke induced small airways alterations in rats.

This study investigated the effect of cigarette smoke exposure and the potential protection N-acetylcysteine (NAC) in rat lungs. Forty-eight rats were exposed to cigarette smoke (CS) for 10 weeks, without (CS group) or with (CS+NAC group) oral intake of NAC 200 mg x rat(-1) x day(-1), or to fresh air (Control). All rat lungs were assessed in terms of lung function, ventilation distribution (nitrogen, helium and sulphur hexafluoride phase III slopes), and morphometry (airway wall thickening of small, medium and large bronchi). The small bronchi, defined as the airways with an internal perimeter <1,000 microm showed significantly thicker airway walls in the CS than in the Control group. By contrast, no airway wall thickening was observed in the CS+NAC group with respect to Control. Except for decreased lung volumes and compliance in CS and CS+NAC groups, which were entirely attributable to smaller body weight gain, lung function was indistinguishable from Control. Phase III slopes were significantly increased only in the CS group. In conclusion, smoke-induced alterations in the rat lungs were reflected in wall thickening of the small bronchi and increased ventilation maldistribution. These smoke-induced morphometric and ventilation distribution alterations were prevented by N-acetylcysteine.     

Histopathologic changes induced by cellophane wrapping of the pancreas are unaffected by cigarette smoke exposure in hamsters

This study tests whether exposure to cigarette smoke alone or combined with cellophane wrapping of the pancreas increases the development of microscopic abnormalities in the pancreas of Syrian golden hamsters. Ninety hamsters were randomly divided into 4 groups. Thirty-five hamsters were exposed to 3 continuous hours of cigarette smoke daily for 3 months following celiotomy to cellophane wrap the gastric lobe of the pancreas (group 1). Thirty-two hamsters were not exposed to continuous cigarette smoke and had the wrap surgery alone (group 2). Twelve hamsters were exposed to cigarette smoke and had no surgery (group 3). Eleven hamsters had no exposure to cigarette smoke and no surgery (group 4). All of the hamsters were sacrificed after 3 months. The gastric (wrapped) and splenic (unwrapped) lobes of the pancreas were reviewed grossly and histologically. In all 4 groups, there were no gross abnormalities in either lobe of the pancreas. Histopathologic evaluation of the gastric lobes from group 1 showed that 13 of 35 lobes (37%) had pancreatitis (11 chronic, 1 acute, and 1 both). In group 2, 12 of 32 (38%) gastric lobes had pancreatitis (10 chronic, 2 acute). The incidence of pancreatitis in groups 1 and 2 was significantly higher than in groups 3 (0/12; p < 0.04) and 4 (0/11; p < 0.03), respectively. A significantly lower incidence of pancreatitis was found in the splenic lobes of all 4 groups when compared to gastric lobes in groups 1 and 2. Three of the 67 cellophane-wrapped glands had ductal hyperplasia. The effects of cellophane wrapping of the pancreas, both in the wrapped and unwrapped areas, induced changes of pancreatitis and hyperplasia that may be preneoplastic. Cigarette smoking, alone or combined with cellophane wrapping, did not cause these changes. Longer exposure to cigarette smoke may be needed to cause premalignant changes in the hamster pancreas.     

Preferential recruitment of neutrophils by endothelin-1 in acute lung inflammation induced by lipopolysaccharide or cigarette smoke

This study examined the role of endothelin-1 (ET-1) in recruiting inflammatory cells to the lung after induction of injury with either lipopolysaccharide (LPS) or cigarette smoke. Hamsters injected with either ET-1 or its precursor peptide (Big ET-1) prior to treatment with LPS or cigarette smoke had markedly increased concentrations of neutrophils in bronchoalveolar lavage fluid (BALF) despite a reduction in total numbers of BALF leukocytes. Furthermore, the effect of ET-1 on smoke-exposed animals was reversed by addition of an endothelin-A receptor antagonist. These results are consistent with preferential recruitment of neutrophils by ET-1, and suggest that inhibition of this proinflammatory mediator may decrease acute pulmonary inflammation associated with cigarette smoke and other pulmonary toxins.     

The effect of cigarette smoke on bleomycin-induced pulmonary fibrosis in hamsters

To investigate the effect of cigarette smoke on the development of bleomycin (BLM)-induced pulmonary fibrosis in hamsters, four experimental groups were studied: a control group (C), a cigarette smoke-inhaled group (T), a BLM-administered group (B), and a cigarette smoke-inhaled plus BLM-administered group (TB). Groups T and TB were exposed to sidestream smoke of cigarettes for 30 min/day, 5 days/wk. Groups B and TB were administered 0.5 mg BLM hydrochloride per 100 g body weight endotracheally once on day 30 (Day 0) after housing start. Quantitative morphometry of the lungs revealed that Group TB showed less lung fibrotic change compared with Group B, but based on qualitative observation, the fibrotic lesions of Group TB were intermingled with slight emphysematous changes. Neutrophils in bronchoalveolar lavage fluid were remarkably increased in both the groups, with a peak on Day 1, but the increase in Group TB lasted longer. Alveolar macrophages were increased in both smoking groups (T and TB) compared to the non-smoking groups (C and B). These results suggest that cigarette smoke reduces BLM-induced lung fibrotic changes; however, it simultaneously causes derangement of alveolar architecture. The persistence of increased neutrophils in the early phase after BLM accompanied by exposure to cigarette smoke may play an important role in the mechanism by which smoke ameliorates the effect of BLM.     

砷和香烟烟气溶液对氧化应激的协同作用

目的研究亚砷酸钠和香烟烟气溶液联合作用对大鼠淋巴细胞氧化应激的影响，并探讨两者对氧化应激的影响是否存在交互作用。方法大鼠淋巴细胞分为4组：亚砷酸钠单独作用组、香烟烟气溶液单独作用组、两者联合作用组和对照组，染毒后用流式细胞术检测细胞内活性氧的含量，用微量荧光法检测细胞内丙二醛含量，用彗星实验检测细胞的DNA损伤，同时采用2×2析因设计研究两者的交互作用。结果亚砷酸钠单独作用组、香烟烟气溶液单独作用组和两者联合作用组细胞内的活性氧含量、丙二醛含量、彗星尾长和细胞拖尾率均高于对照组。析因设计分析结果表明两者对细胞内活性氧含量、丙二醛含量及彗星尾长的影响存在交互作用。结论亚砷酸钠和香烟烟气溶液对大鼠淋巴细胞氧化应激的影响存在交互作用，交互作用方式为协同作用。     

Bronchoconstriction and apnea induced by cigarette smoke: Nicotine dose dependence

Recently, evidence was presented to suggest that nicotine absorbed from cigarette smoke was the main cause of smoke-induced bronchoconstriction (Hartiala et al., J Appl Physiol (1985) 59(1): 64–71). However, due to the qualitative nature of the data, it remains unclear whether cigarette-smoke-induced bronchoconstriction is related to the nicotine content of the smoke in a dose-dependent manner. Experiments were performed on intact anesthetized dogs (n = 6). Each animal spontaneously inhaled 300 cc smoke containing low (0.37 mg), medium (1.46 mg), or high (1.80 mg) levels of nicotine. Isometric tension was measured in an isolated tracheal segment not exposed to the smoke as an index of bronchoconstriction. In all dogs there was a nicotine dose-dependent increase in tracheal tension. The time in expiration (T_e) in the breath following smoke inhalation was prolonged, the magnitude of prolongation being dependent upon the nicotine content of the smoke. These results suggest that bronchoconstriction and changes in T_e induced by cigarette smoke are nicotine-dependent.     

Prostacyclin prevents pulmonary endothelial cell apoptosis induced by cigarette smoke

RATIONALE: Impaired endothelial cell-dependent vasodilation, inflammation, apoptosis, and proliferation are manifestations of endothelial dysfunction in chronic obstructive pulmonary disease (COPD). Prostacyclin (PGI(2)) is a major product of the cyclooxygenase pathway with potent vasodilatory and antimitogenic properties and may be relevant to endothelial dysfunction in COPD. OBJECTIVES: To determine if PGI(2) expression is altered in smoking-related lung disease and if it may be protective in COPD-associated endothelial dysfunction. METHODS: We evaluated, by immunohistochemistry, Western blotting, and polymerase chain reaction, human emphysema tissue compared with normal tissue for expression of prostacyclin synthase (PGI(2)S). We examined the effects of cigarette smoke extract (CSE) and aldehyde components on eicosanoid expression in primary human pulmonary microvascular endothelial cells. Finally, we used a murine model of lung-specific PGI(2)S overexpression and in vitro studies to determine if PGI(2) expression has protective effects on cigarette smoke-induced endothelial apoptosis. MEASUREMENTS AND MAIN RESULTS: Human emphysema lung tissue exhibited lower PGI(2)S expression within the pulmonary endothelium than in normal lung. In vitro studies demonstrated that CSE, and in particular the alpha,beta unsaturated aldehyde acrolein, suppressed PGI(2)S gene expression, whereas CSE significantly induced the upstream mediators COX-2 and cytosolic phospholipase A2 in human pulmonary microvascular endothelial cells. Mice with lung-specific PGI(2)S overexpression exhibited less endothelial apoptosis after chronic smoke exposure. In vitro, iloprost exhibited protective effects on CSE-induced apoptosis. CONCLUSIONS: PGI(2) has protective effects in the pulmonary vasculature after acute and chronic cigarette smoke exposure. An imbalance in eicosanoid expression may be important to COPD-associated endothelial dysfunction.     

香烟烟雾对细胞生物学功能的影响

香烟烟雾中含有大量的化学有毒物质,其颗粒物和挥发性有机物可不同程度地造成炎症的产生、细胞毒性增加、染色体损伤和DNA链断裂,从而引起慢性阻塞性肺疾病、肺癌等疾病的发生.氧化应激机制是目前研究的热点.本文主要从吸烟与呼吸系统疾病、香烟烟雾对细胞的损伤机制、香烟烟雾对气道上皮细胞的作用三大方面对香烟烟雾对细胞生物学功能的影响进行综述,有助于呼吸道疾病的诊断和治疗.     

香烟烟雾提取物致大鼠膈肌细胞氧化损伤

目的研究经香烟烟雾提取物（CSE）刺激后大鼠膈肌细胞8一羟基脱氧鸟苷（8-OHdG）含量的变化以及细胞内活性氧（ROS）水平和8-羟基鸟嘌呤DNA糖苷酶1（OGGl）表达对8．OHdG含量变化的影响。方法用不同浓度CSE分别刺激大鼠膈肌细胞24、48和72h后,采用高效液相色谱．电化学法（HPLC—ECD）检测大鼠膈肌细胞8．OHdG的含量,流式细胞术检测大鼠膈肌细胞ROS水平,采用实时定量PCR检~IJOGG!mRNA水平,用Western印迹法检测OGGl蛋白水平。结果经相同CSE浓度分别刺激大鼠膈肌细胞24、48和72h后,大鼠膈肌细胞中8-OHdG含量、ROS水平及OGGlmRNA和蛋白水平均无明显差异。但经不同浓度CSE刺激相同时间后,10．00％CSE和20．00％CSE刺激组大鼠膈肌细胞8-OHdG含量明显高于对照组和5．00％CSE刺激组（P〈0．05）;大鼠膈肌细胞内ROS水平、OGGlmRNA和蛋白水平较对照组均明显升高（P〈0．05）;大鼠膈肌细胞8-OHdG含量与其ROS水平呈明显正相关（r=0．826,P：0．000）;经CSE刺激后,大鼠膈肌细胞OGGlmRNA和蛋白水平均高于对照组（P〈O．05）,但大鼠膈肌细胞8．OHdG含量与其OGGlmRNA和蛋白水平无明显相关（r=0．373,P=0．254;r=0．329,P=0．296）。结论CSE刺激可引起大鼠膈肌细胞8-OHdG升高,8-OHdG含量与ROS水平有关,但与其修复酶OGGl表达水平无明显相关。     

香烟烟雾刺激诱导肺动脉高压动物模型的构建

目的 探讨利用单纯香烟烟雾刺激造模能否有效构建肺动脉高压疾病模型.方法 把20只清洁级SD大鼠,随机分为对照组(9只)、肺动脉高压(模型)组(11只),用香烟烟雾刺激的方法诱导肺动脉高压模型.在造模满4个月时检测各组大鼠血流动力学指标,取肺组织制作病理切片,比较两组大鼠的肺血管重构程度.结果 与对照组相比,模型组右室收...     

Lung inflammation in rats following subchronic exposure to cigarette mainstream smoke

Female Sprague-Dawley rats were exposed to mainstream smoke from standard reference cigarettes and a nontobacco cellulose cigarette for 35 days. Whole smoke and smoke fractions were investigated. Lung inflammation was evaluated by differentiation of bronchoalveolar lavage cells and lymphocytes in thoracic lymph nodes. Histopathological changes in the nose and larynx were assessed. Results showed that the particulate phase of cigarette mainstream smoke is mostly responsible for inflammation in the lung (neutrophil increase up to 240-fold) and hyperplastic and metaplastic epithelial changes in the larynx, whereas irritative volatile constituents in the gas phase are mostly responsible for changes in the nose.     

Bronchoconstriction and delayed rapid shallow breathing induced by cigarette smoke inhalation in anesthetized rats

Bronchomotor and ventilatory responses to inhalation of cigarette smoke (50% concentration, 6 ml) were studied in anesthetized and vagotomized Sprague-Dawley rats. Low-nicotine cigarette smoke did not cause any detectable delayed response, whereas high-nicotine cigarette smoke induced rapid, shallow breathing, and a marked increase in airway resistance (R_L). The increase in f reached a peak (Δf=43±8%) at the 5th breath after the onset of smoke inhalation, preceding both the decrease in V_T (ΔV_T=−27±4%) and the increase in R_L (ΔR_L=89±19%); the latter 2 reached their peaks at approximately the 10th breath, displaying a similar temporal pattern of responses between them. The bronchomotor response to high-nicotine cigarette smoke was slightly attenuated but not prevented by prior administration of isoproterenol (0.2 mg/kg, intravenously [iv]), nor was the smoke-induced rapid, shallow breathing. In contrast, prior administration of mecamylamine (0.9 mg/kg, iv) completely abolished both the bronchomotor and ventilatory responses to smoke inhalation, indicating that nicotine is the primary causative agent responsible for these changes.     

Bronchoconstriction and delayed rapid shallow breathing induced by cigarette smoke inhalation in anesthetized rats

Bronchomotor and ventilatory responses to inhalation of cigarette smoke (50% concentration, 6 ml) were studied in anesthetized and vagotomized Sprague-Dawley rats. Low-nicotine cigarette smoke did not cause any detectable delayed response, whereas high-nicotine cigarette smoke induced rapid, shallow breathing, and a marked increase in airway resistance (RL). The increase in f reached a peak (delta f = 43 +/- 8%) at the 5th breath after the onset of smoke inhalation, preceding both the decrease in VT (delta VT = -27 +/- 4%) and the increase in RL (delta RL = 89 +/- 19%); the latter 2 reached their peaks at approximately the 10th breath, displaying a similar temporal pattern of responses between them. The bronchomotor response to high-nicotine cigarette smoke was slightly attenuated but not prevented by prior administration of isoproterenol (0.2 mg/kg, intravenously [iv]), nor was the smoke-induced rapid, shallow breathing. In contrast, prior administration of mecamylamine (0.9 mg/kg, iv) completely abolished both the bronchomotor and ventilatory responses to smoke inhalation, indicating that nicotine is the primary causative agent responsible for these changes.     

砷和香烟烟气溶液联合作用对大鼠淋巴细胞凋亡的影响

目的研究亚砷酸钠和香烟烟气溶液(CSS)联合作用对Wistar大鼠淋巴细胞凋亡的影响。方法按2×2析因设计将大鼠淋巴细胞分为4组:对照组、亚砷酸钠组、CSS组、联合作用组。磷脂酰丝氨酸外翻分析法检测各组细胞凋亡情况.并检测各组细胞的Alamar Blue还原率以反映细胞生长代谢情况。结果亚砷酸钠组(1043.47±55.25)、CSS组(1186.52±48.90)和联合作用组(1650.64±89.65)凋亡细胞数明显高于对照组(861.22±42.67,P<0.05);各染毒组的细胞Alamar Blue还原率均明显低于对照组(P<0.05)。析因设计方差分析结果表明亚砷酸钠和CSS对细胞凋亡具有协同式交互作用(F=10.39,P<0.05);而二者对细胞Alamar Blue还原率的影响未见交互作用(F=0.00,P>0.05)。结论亚砷酸钠和CSS均促进大鼠淋巴细胞凋亡,并存在协同式交互作用。     

Tumors and hyperplastic lesions in Syrian hamsters following transplacental and neonatal treatment with cigarette smoke condensate

Summary Cigarette smoke condensate (CSC) in olive oil was injected into outbred Syrian hamsters: in adults i. p. on the 10th–14th days of gestation, total dose 1.5–2.5 mg/g b. 2.; in 12 to 14-days-old animals s. c., total dose 0.5–1.5 mg/animal. Following 15–25 months of observation benign and malignant neoplasms of various location were found in 2/58 (3.4%) females, treated during pregnancy; in 17/51 (33.3%) of their transplacentally exposed offsprings; in 5/53 (9.4%) of neonatally treated hamsters. In the last two groups females were more affected than males. Most frequently occurred tumors of adrenal glands, pancreas, female sex organs, and liver. No tumors appeared in controls, either untreated or injected with olive oil. In addition, hyperplastic lesions, in particular multiple liver cysts and cholangiomatosis were also observed, mainly in animals exposed transplacentally and as neonates.