Expression of Peroxiredoxins and Pulmonary Surfactant Protein A Induced by Silica in Rat Lung Tissue

Silicosis is one of the most serious occupational diseases in China and dates back to centuries ago. In this study, we successfully established a rat model of silicosis by intratracheal silica injection for 28 days and determined hydroxyproline levels to evaluate collagen metabolism in lung homogenates. Oxidative stress status was evaluated by detecting catalase and glutathione peroxidase activities.

Effect of sevoflurane on tissue permeability of lung ischemia-reperfusion injury in rats

Objective:To investigate the effect of sevoflurane on tissue permeability of lung ischemiareperfusion injury(LIRI)in rats.Methods:A total of 45 wistar rats were randomly divided into3 groupsⅠ,Ⅱ,Ⅲ.Modified Eppinger method was adopted to establish the rat lung ischemiareperfusion injury model.GroupⅠserved as the control group,groupⅡas ischemia reperfusion group,groupⅢas sevoflurane ischemia-reperfusion group.Blood gas index,lung permeability index(LPI)change,lung tissue pathology change and lung water content were observed and compared between groups of rats at different time points.Results:During ischemia reperfusion,all rats kept balance of the MAP during different time points,SPO_2 of groupⅡandⅢdecreased significantly thanⅠgroup(P<0.05);after reperfusion lung permeability index in GroupⅡandⅢwas higher than the control group significantly(P<0.05),120 min after reperfusion LPI change and iujury of groupⅢwas significantly lower thanⅡgroup(P<0.05);interstitial and alveolar cavity effusion in of groupⅢwere lower than that of groupⅡ.Conclusions:Sevoflurane pretreatment can reduce the lung tissue permeability,and LIRI plays a protective role in LIRI.

Effects of Formaldehyde Inhalation on Lung of Rats

Objective To analyze protein changes in the lung of Wistar rats exposed to gaseous formaldehyde (FA) at 32-37 mg/m3 for 4 h/day for 15 days using proteomics technique. Methods Lung samples were solubilized and separated by two-dimensional electrophoresis (2-DE), and gel patterns were scanned and analyzed for detection of differently expressed protein spots. These protein spots were identified by MALDI-TOF-MS and NCBInr protein database searching. Results Four proteins were altered significantly in 32-37 mg/m3 FA group, with 3 proteins up-regulated, 1 protein down-regulated. The 4 proteins were identified as aldose reductase, LIM protein, glyceraldehyde-3-phosphate dehydrogenase, and chloride intracellular channel 3. Conclusion The four proteins are related to cell proliferation induced by FA and defense reaction of anti-oxidation. Proteomics is a powerful tool in research of environmental health, and has prospects in search for protein markers for disease diagnosis and monitoring.

Dimethoate Induced Oxidative Damage and Histopathological Changes in lung of Adult rats:Modulatory Effects of Selenium and/or Vitamin E

Objective To determine the efficiency of selenium and/or vitamin E to alleviate lung oxidative damage induced by dimethoate, an organophosphorus compound. Methods Adult Wistar rats were exposed during 30 days either to dimethoate （0.2 g/L of drinking water）, dimethoate＋selenium （0.5 mg/kg of diet）, dimethoate＋vitamin E （100 mg/kg of diet）, or dimethoate＋selenium＋vitamin E. Results Exposure to dimethoate caused oxidative stress in lung evidenced by an increase of malondialdehyde, protein carbonyl groups and advanced oxidation protein products. An increase in glutathione peroxidase, superoxide dismutase, catalase and a decrease in acetylcholinesterase and butyrylcholinesterase activities, glutathione, non-protein thiols and vitamins C levels were observed. Histopathological changes in lung tissue were noted as emphysema, hemorrhages and hemosiderin deposits. Co-administration of selenium or vitamin E to the diet of dimethoate treated rats ameliorated the biochemical parameters as well as histological impairments. The joint effect of these elements was more powerful in antagonizing dimethoate-induced lung oxidative damage. Conclusion We concluded that selenium and vitamin E ameliorated the toxic effects of this pesticide in lung tissue suggesting their role as potential antioxidants.

Exercise Training Attenuated Chronic Cigarette Smoking-induced Up-regulation of FIZZ1/RELMα in Lung of Rats

FIZZ/RELM is a new gene family named ＂found in inflammatory zone＂ （FIZZ） or ＂re- sistin-like molecule＂ （RELM）. FIZZ1/RELMct is specifically expressed in lung tissue and associated with pulmonary inflammation. Chronic cigarette smoking up-regulates FIZZ 1/RELMct expression in rat lung tissues, the mechanism of which is related to cigarette smoking-induced airway hyperresponsive- ness. To investigate the effect of exercise training on chronic cigarette smoking-induced airway hyper- responsiveness and up-regulation of FIZZ1/RELMct, rat chronic cigarette smoking model was estab- lished. The rats were treated with regular exercise training and their airway responsiveness was meas- ured. Hematoxylin and eosin （HE） staining, immunohistochemistry and in situ hybridization of lung tissues were performed to detect the expression of FIZZ1/RELMct. Results revealed that proper exercise training decreased airway hyperresponsiveness and pulmonary inflammation in rat chronic cigarette smoking model. Cigarette smoking increased the mRNA and protein levels of FIZZ1/RELMct, which were reversed by the proper exercise. It is concluded that proper exercise training prevents up-regulation of FIZZ1/RELMct induced by cigarette smoking, which may be involved in the mechanism of proper exercise training modulating airway hyperresponsiveness.

Heme Oxygenase-1 Expression in Rats with Acute Lung Rejection and Implication

This study investigated the expression of hemeoxygenase-1 （HO-1） in rats with acute lung rejection and its implication. A valid rat orthotopic left lung transplantation model （SD rat→Wistar rat） was established by using an improved three-cuff anastomosis technique. The rats were divided into control group, CoPP （HO-1 inducer）-treated group and ZnPP （HO-1 inhibitor）-treated group. The severity of acute rejection was graded on the basis of the morphologic changes of the lung samples stained with HE. The expression of HO-1 protein in lung tissue was detected by using immunohistochemistry and Western blot, and HO-1 mRNA activity was assayed by RT-PCR. The results showed that the expression of HO-1 protein was significantly increased with the acute rejection grading in rats （P〈0.01）. As compared with control and ZnPP-treated groups, the severity of acute rejection was not alleviated and the grade not reduced significantly in CoPP-treated group （P〉0.05）. It was concluded that HO-1 protein might be involved in the pathological process of post-graft acute rejection. The expression of HO-1 protein was increased gradually with aggravation of acute rejection, and HO-1 protein might be used as an index to monitor acute rejection after lung transplantation.

The Mechanism of Acute Lung Injury Induced by Nickel Carbonyl in Rats

Nickel carbonyl is a highly toxic metal compound produced from the reaction that occurs between nickel and carbon monoxide under pressure. As previously reported, nickel carbonyl can cause acute aspiration pneumonia, and animal experiments showed it was toxic to animal lung, liver, brain, and other vital organs[1]. However, few studies have investigated nickel carbonyl poisoning in humans.

The Role of Nitric Oxide in Hyperoxic Lung Injury in Premature Rats

To investigate the role of nitric oxide (NO) in hyperoxic lung injury, the 3 day old preterm rats were randomly assigned to four groups: group I (hyperoxia group), group Ⅱ (hyperoxia+N w nitro L arginine methyl ester (L NAME) group), group Ⅲ (air group), and group Ⅳ (air+L NAME) group. Group Ⅰ and Ⅱ were exposed to ≥90 % O 2 for 3 or 7 days. Group Ⅱ and Ⅳ received subcutaneous L NAMEy on daily basis (20 mg/kg). After 3 day or 7 day exposure, the lung wet weight/dry weight ratio (W/D), total protein and malondialdehyde (MDA) in bronchoalveolar lavage fluid (BALF) and lung pathology were examined in all groups. NO content, expression of endothelial NOS (eNOS) and inducible NOS (iNOS) in lungs were measured in group Ⅰ and Ⅲ. Our results showed that after 3 day exposure, group Ⅰ appeared acute lung injury characterized by the increase of MDA content ( P <0.01) and the presence of hyperaemia, red cell extravasation and inflammatory infiltration; after 7 day exposure, except MDA, total protein and W/D were also increased in comparison with group Ⅲ ( P <0.01, 0.05), pathological changes were more severe than those after 3 day exposure. After 3 and 7 day exposure, total protein in group Ⅱ was significantly increased as compared with group Ⅰ ( P <0.01 for both). The pulmonary acute inflammatory changes were more obvious in group Ⅱ than in group Ⅰ. Occasionally, mild hemorrhage was detected in the lungs of group Ⅳ. BALF protein content in group IV was higher than that in group Ⅲ after 7 day exposure ( P <0.01). After 3 and 7 day exposure, NO content in BALF were all significantly elevated in group Ⅰ as compared with group Ⅲ ( P <0.01 for all). In the lungs of group Ⅰ, strong immunostaining for iNOS was observed in airway and alveolar epithelia, inflammatory cells, which were stronger than those in group Ⅲ. Expression of iNOS in rats after 7 day hyperoxic exposure was stronger than that after 3 day exposure. Shortly after 7 day exposure, stronger immunostaining for eNOS in airway epithelia in group Ⅰ than that in group Ⅲ was seen. Our study suggested that treatment with L NAME worsened acute hyperoxic lung injury in preterm rats and also had a deleterious effect on the rats exposed to air, indicating that endogenous nitric oxide may play a protective role in rats under both physiological and hyperoxic status. Hyperoxia can significantly upregulate the expression of iNOS and eNOS in inflammatory cells, epithelia in the lungs of preterm rats, promote NO generation, which suggests that endogenous NO may mediate the hyperoxic pulmonary damage. Over stimulation of iNOS may contribute to the pathogenesis of hyperoxic lung injury. NO may have dual roles in pulmonary oxygen toxicity.

Anastomotic techniques for rat lung transplantation

The first lung transplantation in the rat was achieved by Asimacopoulos et al using sutured anastomoses in 1971.Subsequent development of a cuffed technique to construct the anastomoses by Mizuta and colleagues in 1989 represented a breakthrough that resulted in simplification of the procedure and shorter warm is-chemic times.Since then,a number of further variations on the technique of rat lung transplantation have been described.In spite of this,the procedure remains technically demanding and involves a long learning curve.This minireview describes the following new technical safeguards to further evolve the technique for cuffed anastomoses in rat lung transplantation:the use of anatomical landmarks to avoid twisting of the everted donor pulmonary vein and bronchus in the cuff,the use of the cuff tie as a landmark to avoid twisting of the anastomotic cuffs relative to the recipient vessels,distal ties on the recipient vessels to achieve a bloodless field and triangulation of the venotomy to avoid pulmonary vein tearing.

Effects of Silica on Serum Phospholipid,Lipid Peroxide and Morphological Characteristics of Rat Lung

The effects of instilled silica have been studied on the serum-phospholipid (PL), lipid peroxide (LPO) and histopathology of rat lung up to 140 days from the first day of instillation. Silica induced relatively higher serum-PL throughout the experiment. The level of LPO also increased appreciably. They presented positive linear correlation. The early lesion was acute alveolitis with silica particles. These lesions became silicotic nodules on the 30th day, which then were enlarged gradually and fused by fibrosis. Alveolar macrophages (AM) were activated and surface structure was damaged. These results indicate that instilled sillca can induce lipid peroxidation of cell membrane and selective accumulation of lung PL

Attenuation of Nitric Oxide Synthase Gene Expression in Rat Lung Induced by Hypoxia

In order to investigate the role of nitric oxide(NO) in pathogenesis of hypoxic pulmonary hypertension(HPH), the mean pulmonary arterial pressure(mPAP), mRNA expression of NO synthase(NOS) in lung tissues, cGMP levels, and their relationships were studied in rats exposed to hypoxia from 8 h to 28days. The results showed that mPAP began to increase in animals exposed to 10 % O2 for 8 h. Moreover, the longer the exposure, the higher the mPAP.Northern blot analysis and dot blot hybridization indicated that mRNA expression of NO in lung tissues of hypoxic rats tended to decrease with exposure days, but that of β-actin which acted as a control did not alter. The cGMP levels of plasma and lung tissues in hypoxic rats also inclined to be lower with exposure days. A marked negative correlations between the changes of cGMP levels and those of mPAP were found. It was suggested that mRNA expression of NOS gene was attenuated in hypoxic lung tissues, which may be one of important pathogenetic mechanisms of HPH.

PROMOTION OF CHEMICAL CARCINOGENESIS AND P53 EXPRESSION BY REDUCTION OF SUPEROXIDE DISMUTASE ACTIVITY IN THE LUNG OF RAT IN VIVO

In the present experiment,an inhibitor of superoxide dismutase(SOD),diethyldithiocarbamate(DETC),was used to decrease SOD activity for the observation of the relation between SOD activity and carcinogenesis and the expression of P53 protein in vivo.144 Wistar rats were used for the Present study.The results showed that the SOD activity reduction by DETC resulted markedly in the promotion of the carcinogenesis and the expression of P53 protein in the lung tissues,but the increase of SOD activity by the addition of plus SOD inhibited the pathological changes significantly.The frequency of the pathological lesions and Positive P53 expression are 36/42 and 8/42 in the animals without DETC and SOD:16/52 and 4/52 in the animals with SOD and 46/50 and 26/50 in the animals with DETC respectively.The results reported in this Paper suggest that:(1) the decrease of SOD activity enhanced the carcinogenesis induced by chemical carcinogen;(2) P53 gene may be associated with the process of tumorigenesis;and(3) at the same time the abnormal expression of P53 protein may be associated with the transition from premalignant lesions to carcinoma.

Retinoic Aacid Diminished the Expression of MMP-2 in Hyperoxia-exposed Premature Rat Lung Fibroblasts through Regulating Mitogen-activated Protein Kinases

This study examined the effects of retinoic acid （RA）, PD98059, SP600125 and SB203580 on the hyperoxia-induced expression and regulation of matrix metalloproteinase-2 （MMP-2） and metalloproteinase-2 （TIMP-2） in premature rat lung fibroblasts （LFs）. LFs were exposed to hyperoxia or room air for 12 h in the presence of RA and the kinase inhibitors PD98059 （ERK1/2）, SP600125 （JNK1/2） and SB203580 （p38） respectively. The expression levels of MMP-2 and TIMP-2 mRNA were detected by semi-quantitative reverse transcription polymerase chain reaction （RT-PCR）. MMP-2 activity was measured by zymography. The amount of p-ERK1/2, REK1/2, p-JNK1/2, JNK1/2, p-p38 and p38 was determined by Western blotting. The results showed that： （1） PD98059, SP600125 and SB203580 significantly inhibited p-ERK1/2, p-JNK1/2 and p-p38 respectively in LFs; （2） The expression of MMP-2 mRNA in LFs exposed to hyperoxia was decreased after treatment with RA, SP600125 and SB203580 respectively （P0.01 or 0.05）, but did not change after treatment with PD98059 （P0.05）. Meanwhile, RA, PD98059, SP600125 and SB203580 had no effect on the expression of TIMP-2 mRNA in LFs exposed to room air or hyperoxia （P0.05）; （3） The expression of pro- and active MMP-2 experienced no change after treatment with RA or SP600125 in LFs exposed to room air （P0.05）, but decreased remarkably after hyperoxia （P0.01 or 0.05）. SB203580 inhibited the expression of pro- and active MMP-2 either in room air or under hyperoxia （P0.01）. PD98059 exerted no effect on the expression of pro- and active MMP-2 （P0.05）. It was suggested that RA had a protective effect on hyperoxia-induced lung injury by down-regulating the expression of MMP-2 through decreasing the JNK and p38 activation in hyperoxia.

Cigarette Smoke Induces Apoptosis by Activation of Caspase-3 in Isolated Fetal Rat Lung Type II Alveolar Ep-ithelial Cells <i>in Vitro</i>

Smoking during pregnancy is a major source of fetal exposure to numerous harmful agents present in tobacco smoke. Lung development involves complex biochemical processes resulting in dramatic changes which continue even after birth. In addition to type I cells which form the blood-air barrier, type II alveolar epithelial (AE) cells have important and diverse functions related to immunological protection and stabilization of the alveolus through synthesis and secretion of the pulmonary surfactant. Apoptosis or programmed cells death is an important physiological process during lung embryogenesis and for the proper maintenance of homeostasis. Caspases are proteases that play important roles in regulating apoptosis. Caspase-3 is the key executioner caspase in the cascade of events leading to cell death by apoptosis. We explored the hypothesis that cigarette smoke extract (CSE) induces apoptosis in fetal rat lung type II AE cells by activation of caspase-3. To analyze these factors, isolated fetal rat lung type II AE cells were used. The cells were exposed to different concentrations of CSE (5%, 10% or 15%) (v/v) for 60 min. The results of the present study showed that CSE induced apoptosis in fetal rat lung type II AE cells with a significant increase (p 0.05) in caspase-3 activity and decrease in cell proliferation at CSE concentrations of 10% and 15% (v/v). These observations indicate that cigarette smoke extract induces apoptosis by activation of caspase-3 in fetal rat lung type II AE cells in a dose-dependent manner and may potentially alter the regulated development of the lung and the appearance of the surfactant-producing type II alveolar cells which are critical for the establishment of adequate gas exchange at birth.

TEMPORAL EXPRESSION OF NOTCH RECEPTORS DURING LUNG DEVELOPMENT IN RAT

Objective To investigate the temporal expression of Notch receptors in developing lungs of rats and to explore the regulating role of Notch in lung development. Methods We studied the expression of Notch1,2,3 isforms in embryonic days 18,20,21 and postnatal days 1,4,7,14, 21 rat lungs. Six rats of each group were used to assess lung histologic changes by HE staining and expression of Notch in lungs by immunohistochemistry. Total RNA was extracted by Trizol reagent from the frozen lung tissues. mRNA levels of Notch were measured by reverse transcription polymerase chain reaction (RT-PCR). Results It is showed that Notch_ 1-3 mainly localized in the airway surface epithelium、alveolar epithelium during the psdueoglandular stage, and reached the peaks at canalicular period. The expression patterns of Notch_ 1-3 were changed with the fetal age. Conclusion These results support multiple roles for Notch1,2,and 3 receptor activation during lung development, probably not only modulating the process of branching morphogenesis but also involved in determining the cell differentiation fate in fetal alveolar epithelium.

Effects of Hyperoxia on Mitochondrial Multienzyme Complex Ⅲ and Ⅴ in Premature Newborn Rat Lung

To investigate the effects of hyperoxia on mitochondrial multienzyme complex Ⅲ （cytochrome, Cytb） and Ⅴ （ATPase6, 8） in premature newborn rat lung, the 1-day-old preterm SD rats were randomly assigned to hyperoxia group and air group, The rats in hyperoxia group were continuously exposed to 85% oxygen and those in air group to room air. After 1, 4, 7, 10, 14 day（s） of exposure, these rats were killed, total lung RNA was extracted and Cytb, ATPase6, 8 mRNA were detected by reverse transcription polymerase chain reaction （RT-PCR）. Western blotting was used to detect the expression of Cytb protein in lung tissue. The results showed that compared with air group, Cytb mRNA expression was significantly increased （P〉0,05） after 1, 4 day（s） of exposure. The general tendency decreased after 7 days, and its expression became weak but difference in mRNA expression between the two groups was not significant （P〉0.05）. ATPase6 mRNA expression was significantly increased 1 day after the exposure （P〈0.05） and did not show any significant change 4, 7, 10 days after the exposure （P〉0.05）. At the 14th day, ATPase6 mRNA expression was significantly increased （P〈0.05）, ATPase8 mRNA expression did not show any significant change 1, 4, 10 day（s） after the exposure （P〉0.05）, At the 7th and 14th day, ATPase8 mRNA expression was significantly increased （P〈0.05）. Western blotting showed that Cytb protein expression was increased 1,4 day（s） after the exposure, but the difference between the two groups was not significant （P〉0.05）. The general tendency was decreased after 7 days, and its expression became weak but difference was not significant 7, 10 days after the exposure （P〉0.05）. At day 14 its expression became significantly weak （P〈0.05）. We are led to conclude that exposure to high concentrations of oxygen can significantly change the expression of Cytb and ATPase6, 8, which results in uncoupling of oxidative phosphorylation in mitochondrial respiration chain, and plays an important role in the mechanism of hyperoxia-induced lung injury.

Stereological study of quantitative relationships between morphological and functional changes of the lungs in early phase of blast injury in rats

The morphological and functional changes of the lungs in the early phase of blast injurywere analyzed and related quantitatively in rats with microcomputer-assisted morphometry.It wasfound that（1）significant or partial correlation exists between stereological and functional indices,（2）changes of the endothelium and epithelium rather than the interstitium contribute to the increase ofharmonic and arithmetic thickness(Tht,Tat)of the air-blood barrier,and（3）the regression equa-tions are as follows:（a）PaO2=3.56+1.62DL（O2）,r=0.678,P=0.032:（b）PaO2=2.99+3.49DL（O2）-0.0005SA+0.003Sc-38.2Vc-0.257Tap-0.028Dt（O2）,ry=0.9999,P=0.008;（c）PaCO2=7.69+0.0001SA-4.35Tat+19.7Tht-46.2Thp-4.4Taen-5.87Taep,ry=0.9999,P=0.014;（d）pH=3.068+0.0005SA-1.79Tat+12.2Tht-50.8Thp-2.52Taint+0.69DL（O2）,ry=0.9999,P=0.10.The significance and application of stereology in theestablishment of the quantitative relationship between morphological and functional indices are dis-cussed.Mathematical models to relate morphometric parameters to functional changes are possible.

Effect of Retinoic acid on Platelet-derived Growth Factorand Lung Development in Newborn Rats

Summary: The influence of platelet-derived growth factor (PDGF) on lung development in newborn rats and the effect of retinoic acid (RA) on PDGF in lung development were investigated. Newborn Sprague-Dawley (SD) rats were randomly assigned to two groups: control group and RA group. The rats in RA group was intraperitoneally injected with all trans-retinoic acid (500 μg/kg every day) for consecutive 3 days after birth, while those in the control group were not subjected to intervention. Immunohistochemical assay was performed to locate the expression of PDGF. mRNA levels of PDGF were measured by reverse transcription polymerase chain reaction (RT-PCR) at age of 1, 3, 5, 7, 10, 14, 21 days. The method of radial alveolar counts (RAC) was used to measure the amount of the alveoli of the lungs. It was found that with increasing days, levels of PDGF-A and PDGF-B changed to verying degrees. RA could elevate significantly the expression levels of PDGF-A mRNA and protein (P<0.01), but not affect the expression levels of PDGF-B mRNA and protein markedly (P>0.05). It is suggested that PDGF might play an important role in lung development. RA can stimulate lung development through increasing the expression levels of PDGF-A mRNA and protein.

Functional changes of pulmonary surfactant in rats with lung injury induced by endotoxin

We studied the functional changes of pulmonary surfactant （PS） in acutelung injury models produced by endotoxin injection (E.coli O55B5) in rats.The sur-face properties of the lung lavage liquid and the total phospholipids （TPL） ex-tracted from it were assessed on a modified Wilhelmy film balance.γ-A isothermof the lavage liquid revealed an increase in minimum surface tension and a de-crease in hysteresis area,recruitment index and stability index,whereas that ofTPL extracted from it did not show any change except for hysteresis area.Thesurface activity correlates positively with the TPL content but negatively with thetotal protein content in the lavage liquid.The findings indicated that there was adysfunction of PS in rats with the lung injury induced by endotoxin,suggestingthat the function deficiency of PS might be caused by decreased phospholipidsand increased proteins in the alveoli.