Effect of intestinal lymphatic pathway on apoptosis of lung tissue in rats by two-hit

AIM: To observe the effects of mesenteric lymph duct ligation on apoptosis of lung tissue,correlated gene expression with apoptosis and TNF-α,IL-6 contents in rats by two-hit.METHODS: 45 Wistar rats were divided into three groups: the ligation group,the non-ligation group and sham group,and the two-hit model was established by means of hemorrhage and LPS treatments.Ligating mesenteric lymph duct was conducted in ligation group.After 24 hours,the pathological sections of lung tissue were prepared for determining the apoptosis rate by TUNEL method and expressions of Bcl-2 and Bax were observed by immunohistochemical test.The lung homogenate was also prepared for determining the contents of TNF-α and IL-6 by ELISA.RESULTS: After two-hit,the apoptosis rate,Bax expression in lung tissue and contents of TNF-α and IL-6 in serum and lung homogenate in non-ligation group were increased and Bcl-2 expression was lower than that in sham group and ligation group significantly (P<0.01,P<0.05).Apoptosis rate in ligation group was no statistics difference with sham group (P>0.05),and the expression of Bcl-2 protein was increased and Bax was lower than that of sham group (P<0.01,P<0.05).CONCLUSION: Blockage of intestinal lymphatic pathway reduces the apoptosis of lung in two-hit rats,and its mechanism might relate to reduced the levels of TNF-α and IL-6 and improved the expression of Bcl-2 protein in lung by the ligation of mesenteric lymph duct.The mesenteric lymph of two-hit might play an important role in the pathogenesis of acute lung injury (ALI).     

Mechanism of mesenteric lymph duct ligation against the renal insufficiency in hemorrhagic shock rats

AIM: To observe the effect of mesenteric lymph duct ligation on free radical and inflammatory mediator in serious hemorrhagic shock rats at different periods, and explore the mechanism of intestinal lymphatic pathway on renal insufficiency. METHODS: 78 male Wistar rats were divided into the sham group, shock group, and ligation group. The model of serious hemorrhagic shock was established in shock group, ligation group, and mesenteric lymph was blocked by ligating mesenteric lymph duct in ligation group after resuscitating. All rats were executed and kidneys were taken out for making homogenate of 10 percent to determine levels of MDA, SOD, NO, NOS, tumor necrosis factor-alpha (TNF-α), interleukin-6 (IL-6) and myeloperoxidase (MPO) at time points after shock 90 min, after transfusion and resuscitate 0 h, 1 h, 3 h, 6 h, 12 h and 24 h. The expression of inducible nitric oxide synthase (iNOS) mRNA in kindey was detected by RT-PCR. RESULTS: The contents of MDA, NO, NOS, TNF-α, IL-6, MPO and iNOS expressions in renal homogenate of shock group were increased after transfusion and resuscitation, and were higher at 6 h and 12 h, and was significantly higher than that in sham group. The acvitity of SOD was significantly lower than that in sham group (P<0.01, P<0.05). The contents of MDA, NO, NOS, TNF-α, IL-6, MPO and iNOS expression in renal homogenate of ligation group after transfusion and resuscitation 6 h, 12 h and 24 h were significantly lower than those in shock group at same points, and the SOD activity was higher (P<0.01, P<0.05). CONCLUSION: The results demonstrate that the ligation of mesenteric lymph duct can antagonise the development of renal failure in serious hemorrhagic shock rats, and its mechanism might relate to reduce the PMN sequestration, decrease the levels of TNF-α and IL-6, inhibit NO production and expression of iNOS mRNA, suppress the release of free radical and consumption of SOD.     

Protective effect of ambroxol against the lung damage in chronically hypoxic rats

AIM: To investigate the effect of ambroxol on pulmonary and vascular injury in chronically hypoxic rats. METHODS: 36 male Wistar rats were randomly divided into 3 groups: normal control,chronically intermittent hypoxia(CIH) and ambroxol precaution group(AP).The CIH and AP groups were made into the chronically hypoxic models.The mean pulmonary artery pressure(PAPM) and the levels of plasma superoxide dismutase(SOD) and plasma nitric oxide(NO),lipid peroxide(LPO) were determined. The levels of the lung homogenates SOD, LPO, NO and the changes in pulmonary vascular structure were also examined. RESULTS: The levels of plasma and lung homogenates SOD,NO in CIH group were respectively significantly lower than that of normal control and AP group( P <0.01),but the levels of plasma and lung homogenates LPO were significantly higher( P< 0.01). PAPM in AP group is significantly lower than that of CIH group( P< 0.01);The damage of pulmonary artery smooth muscle cells and extra cell matrix of AP group is much slighter than that of CIH group. CONCLUSION: Ambroxol might be an effective protector in chronically hypoxic rats.     

Changes of serum levels of inflammatory cytokines in elderly patients with heart failure

AIM: To investigate the relationship between serum levels of TNF-α, sTNFRI, IL-6, IL-10, TGF-β₁ and cardiac function in elderly patients with heart failure.METHODS: The serum levels of TNF-α, sTNFRI, IL-6, IL-10 and TGF-β₁ were determined by ELISA in 112 elderly patients with heart failure and 60 elderly normal subjects.The left ventricular end-diastolic diameter (LVEDD) and left ventricular ejection fraction (LVEF) were measured by color Doppler ultrasonic instrument.RESULTS: (1) Compared with normal subjects group, the serum levels of TNF-α, sTNFRI, IL-6, IL-10 and TGF-β₁ in elderly patients with heart failure were significantly elevated (P<0.05 or P<0.01), and increased gradually with upgrade of cardiac function according to cardiac function classification of New York Heart Association (P<0.05 or P<0.01).(2) The ratio of TNFα/sTNFRI and IL-6/IL-10 in patients with heart failure were notably higher than those in control (P<0.05, P<0.01) and increased gradually with upgrade of cardiac function classification (P<0.05, P<0.01).(3) In heart failure group, a significantly positive correlation was found between serum levels of TNF-α, IL-6 and LVEDD.A significantly negative correlation between serum levels of TNF-α, IL-6 and LVEF was also observed.CONCLUSION: The serum levels of pro-inflammatory cytokines are closely related with cardiac function in elderly patients with heart failure.The balances of TNFα/sTNFRI and IL-6/IL-10 shifted towards inflammatory side.Furthermore, the changes of them reflect the varieties of cardiac function.     

Alteration of AQP2 expression in kidney tissues of emphysema model rats

AIM: To observe the expressions of aquaporin 2 (AQP2) in kidney tissues and the contents of endotoxin (ET), interleukin-1 β (IL-1β), tumor necrosis factor-α (TNF-α) in serum in emphysema model rats, and to investigate the relationship between lungs and kidney in humoral metabolism. METHODS: The rats of emphysema were treated by injecting lipopolysaccharide into the trachea with cigarette smoking. Immunohistochemistry and Western blotting analysis were used to observe the expression of AQP2 in kidney tissues. RT-PCR was applied to detect the expression of AQP2 mRNA in kidney tissues. Blood sample and lung tissue were taken and the levels of ET, IL-1β and TNF-α were measured by radioimmunoassay. RESULTS: AQP2 expression in the kidney tissue in model group was greater than that in control group, and the expression of AQP2 mRNA showed the same results (P<0.01). ET, IL-1β and TNF-α levels in serum and lung tissue in model group were markedly higher than those in control group (P<0.01). CONCLUSION: In the emphysema model rats, AQP2 expression is up-regulated in the kidney tissue. The mechanism of emphysema may be related to increasing the levels of ET, IL-1β and TNF-α in the serum and lung tissue obviously.     

Protective effect of ethyl pyruvate against LPS-induced acute lung injury in dogs with septic shock

AIM:To investigate the effect of ethyl pyruvate (EP) on acute lung injury in dogs with septic shock.METHODS:Twenty dogs with septic shock induced by lipopolysaccharide (LPS) were randomly divided into two groups:dog received placebo (Ringers solution; control group, n=8) or ethyl pyruvate in lactated Ringers solution (0.05 g/kg loading dose over 10 min, thereafter 0.05 g· kg-1·h-1 for 12 h; EP treatment group, n=12).The parameters of respiratory mechanics, including lung dynamic compliance (Cdyn), lung total compliance (Ctot), inspiratory airway resistance (Rawi), peak inspiratory pressure (PIP), work of breathing (WOB), and arterial blood gases were monitored every 4 h after basic measurements (pre-LPS).The contents of TNF-α, IL-6 and IL-10 in serum were also detected by ELISA and compared between two groups.RESULTS:The changes of respiratory mechanics and arterial blood gases were in line with acute lung injury after septic shock induced by LPS.Oxygen index (OI), HCO-3and pH dropped 4 h after septic shock.On the contrary, PCO2 elevated significantly compared with that of septic shock before (P<0.05).Cdyn, Ctot decreased and Rawi, PIP, WOB increased significantly 8 h after septic shock (P<0.05).The changes in parameters of respiratory mechanics and arterial blood gases in control group were more distinguished than those in EP treatment group.There were significantly differences between two groups 8 h after septic shock (P<0.05).Although the significant improvement of respiratory mechanics was not observed, EP did prevent the parameters from worsening further more.Significantly differences between the two groups 12 h after septic shock (P<0.05) were found.Ethyl pyruvate also regulated the network of cytokines:increased the level of TNF-α, IL-6 and reduced the content of IL-10 in serum significantly compared with control group (P<0.05).CONCLUSION:Ethyl pyruvate has protective effects on acute lung injury in dogs with septic shock.     

Effects of silymarin on LPS-induced acute lung injury in rats

AIM:To investigate the effects of silymarin on lipopolysaccharide (LPS)-induced acute lung injury in rats and its possible molecular mechanisms. METHODS:Fifty-eight male SD rats, weighting 230-250 g, were divided into four groups randomly: normal control (n=12); acute lung injury group (n=15), receiving intravenous LPS (O55∶〖KG-*2〗B5, 5 mg/kg); silymarin alone group (50 mg/kg, n=15); intervention group (n=16, receiving silymarin 50 mg/kg and LPS 5 mg/kg). The specimens were collected 6 hours later. The following changes, including blood gas analysis, the lung wet/dry weight ratio, the pulmonary vascular permeability, histological manifestations, lung tissue myeloperoxidase activity, the levels of TNF-α, IL-1β, MCP-1 and SOD, GSH-Px as well as malonaldehyde and conjugated diene in plasma and lung tissue, were observed. RESULTS:Compared with control group, the lungs of the rats in LPS treatment group showed significant hyperemia and spotted hemorrhage. The inflammatory granulocyte infiltrating, diffused alveolar septum thickening and spotted hemorrhage were observed in pathological examinations. The lung wet/dry weight ratio and Evans blue content (per gram) increased significantly after LPS treatment. The myeloperoxidase activity in plasma and lung tissue, the levels of TNF-α, IL-1β, MCP-1 and SOD, GSH-Px as well as malonaldehyde and conjugated diene were increased significantly in LPS treatment group. However, in intervention groups, all the above-mentioned measurements were reversed significantly by silymarin treatment compared with LPS treatment group. CONCLUSION:Silymarin may decrease inflammatory reaction and oxidative stress, and further decrease lung damage induced by LPS in rats, all indicating protection of silymarin against acute lung injury.     

Effects of lidocain and gentamycin on inflammation reaction and wound infection of explosive wound in limb arthrosis after seawater immersion

AIM: To investigate the effects of lidocain and gentamycin on inflammation reaction and wound infection of explosive wound in limb arthrosis after seawater immersion. METHODS: The explosive wound were made in 48 New Zealand white rabbits. All rabbits were randomly divided into 4 groups: lidocain, gentamycin and glutin sponge bound up and immersed in seawater 1 h group (LGGS group, n=12); bactroban and glutin sponge bound up and immersed in seawater 1 h group (BGS group, n=12); 12 layers common gauze bound up and immersed in seawater 1 h group (GS group, n=12) and 12 layers common gauze bound up 1 h group (G group, n=12). The changes of blood WBC, CRP, IL-1, IL-6, TNF-α, MDA and SOD in each group were tested. The bacterial culture was performed in each group after explosion 1 h, 3 d, 7 d and 1 month. RESULTS: Compared with pre-experiment, the WBC was decreased, the IL-6 and TNF-α values were increased significantly (P<0.05, P<0.01). The contents of MDA and SOD activity didn't change markedly in the LGGS group (P>0.05), but the other groups did (P<0.05, P<0.01). 24 gram-position bacteria were found in wounds. Three kinds of condition pathgens were cultured out in the group LGGS on the 3rd day, but none of rabbits were infected. 9 rabbits were infected in the group BGS. All rabbits in the other groups were infected. CONCLUSION: Lindocain and gentamycin used externally to the wound restrain tissue lipid perosidation to some extent and prevent wound infection evidently in explosive wound after seawater immersion.     

Changes of NO- and H2O2-dependent soluble guanylate cyclase pathway in the hypoxic hypercapnic pulmonary hypertension rats

AIM: To study the effect of hypoxia and hypercapnia on nitric oxide (NO) in plasma and superoxide dismutase (SOD), catalase (CAT), soluble guanylate cyclase (sGC), cyclic guanosine monophospholate (cGMP) in lung tissue in rats, and to explore the effect of NO- and H2O2-sGC pathway on the development of the pulmonary hypertension. METHODS: The model of hypoxic and hypercapnic 1, 2, 4-week group (HH 1 week, HH 2 weeks, HH 4 weeks) and control group was set up. NO content in plasma, CAT and SOD in rat lung were determined by spectrophotometry. The sGC activity in lung tissue was detected by enzyme kinetic analysis. cGMP content in lung tissue was examined with ［125I］-radioimmunoassay. RESULTS: The mean pulmonary artery pressure (mPAP) showed significantly higher in HH 1 week, HH 2 weeks and HH 4 weeks groups compared with control group (all P<0.05). NO concentration in plasma, CAT, SOD, basal or nitroprusside-or H2O2- stimulated sGC activity and cGMP concentration in lung homogenates were significantly lower (P<0.05, P<0.01, P<0.01, respectively) in HH 1 week, HH 2 weeks and HH 4 weeks groups compared with control group. CONCLUSION: The inhibition of NO- and H2O2-sGC pathway by hypoxia and hypercapnia plays an important role in the development of pulmonary hypertension.     

Effect of propofol on expression of PKC mRNA in pulmonary injury induced by ischemia-reperfusion in rabbits

AIM: To investigate the effect of propofol on expression of protein kinase C (PKC) mRNA during pulmonary ischemia and reperfusion injury (PIRI) in rabbits. METHODS: Single lung ischemia and reperfusion animal model was used in vivo. The rabbits were randomly divided into three groups (n=9 in each): sham operated group (sham), PIR group (I-R) and PIR+ propofol group (PPF). Changes of several parameters including malondialdehyde (MDA), superoxide dismutase (SOD), wet to dry ratio of lung tissue weight (W/D) and index of quantitative assessment of histologic lung injury (IQA) were measured at 60 minutes after reperfusion in lung tissue. Meanwhile the location and expression of PKC mRNA were observed. Lung tissue was also prepared for light microscopic and electron microscopic observation at 60 minutes after reperfusion. RESULTS: As compared with group I-R, PKC mRNA strongly expressed in intima and extima of small pulmonary artery as well as thin-wall vessels (mostly small pulmonary veins) in PPF group. The average optical density values of PKC-α、δ and θ mRNA in small pulmonary veins PPF in group showed significantly higher than that in I-R group (all P<0.01). SOD increased and MDA, W/D and IQA decreased at 60 minutes after reperfusion in lung tissue (P<0.01 and P<0.05). Abnormal changes of the lung tissue in morphology were lessen markedly in PPF group. CONCLUSIONS: Propofol produces notable protective effects on PIRI in rabbits by activating PKC-α， δ and θ mRNA expression in lung tissue, raising NO level, dropping OFR level and decreasing lipid peroxidation.     

Ulinastatin protects rat pulmonary tissues from paraquat-induced acute injury

AIM: To investigate the protective effects of ulinastatin on the rats with paraquat-induced acute lung injury and its mechanisms. METHODS: The Wistar rats (n=108) were randomly divided into control group, paraquat group and ulinastatin group. The rats in paraquat group and ulinastatin group were given paraquat by gavage, while the rats in control group were given sterile saline by gavage. The rats in ulinastatin group were also given ulinastatin treatment. The serum levels of MDA, SOD, IL-6, IL-10 and TNF-α were measured after 1 d, 3 d, 7 d, 14 d, 21 d and 28 d. The expression levels of p38 MAPK, MMP-2 and TIMP-1 in the lung were also measured. RESULTS: The levels of SOD in 1 d, 3 d and 7 d in paraquat group and ulinastatin group were significantly lower than those in control group (P<0.01). The level of SOD in ulinastatin group was significantly higher than that in paraquat group (P<0.05). The levels of MDA, IL-6, IL-10 and TNF-α in 1 d, 3 d and 7 d in paraquat group and ulinastatin group increased compared with control group (P<0.01), and those in ulinastatin group were significantly lower than those in paraquat group (P<0.05). The levels of p38 MAPK and TIMP-1 in 1 d, 3 d, 7 d, 14 d, 21 d and 28 d in paraquat group and ulinastatin group were higher than those in control group (P<0.01), and those in ulinastatin group was significantly lower than those in paraquat group (P<0.05). The level of MMP-2 in 1 d, 3 d, 7 d, 14 d and 21 d in paraquat group and ulinastatin group increased compared with control group (P<0.01), and that in ulinastatin group was significantly lower than that in paraquat group (P<0.05).CONCLUSION: Ulinastatin protects the lung tissues of rats from paraquat-induced acute lung injury by inhibiting p38 MAPK signaling pathway and ameliorating inflammatory and oxidative responses.     

Effects of diosmin on changes of TNF-α, IL-1β, IL-6, IL-8 and IL-10 in serum and kidney tissues of rats with kidney ischemia and reperfusion

AIM: To observe the effects of diosmin on the production of tumor necrosis factor-α(TNF-α), interleukin-1β(IL-1β), IL-6, IL-8 and IL-10 in serum and kidney tissues of rats with kidney ischemia and reperfusion (I/R). METHODS: Sprague-Dawley rats (180 in total) were randomly divided into 3 groups including sham operation group (sham),I/R group and diosmin+I/R group (diosmin+I/R). At the end of the experiment, the blood and kidney tissues were obtained and TNF-α, IL-1β, IL-6, IL-8 and IL-10 were detected by ELISA. RESULTS: The levels of TNF-α, IL-1β, IL-6, IL-8 and IL-10 in serum and kidney tissues in I/R group and diosmin+I/R group were significantly higher than those in sham group (P<0.01 or P<0.05). Following the development of the pathologic process, the level of TNF-α, IL-1β, IL-6 and IL-8 was significantly increased in I/R group and diosmin+I/R groups, but the level of IL-10 was significantly decreased in I/R group and significantly increased in diosmin+I/R group. The levels of TNF-α, IL-1β, IL-6 and IL-8 in I/R group was significantly higher than those in diosmin+I/R group (except TNF-α at 1 h in diosmin+I/R group). The level of IL-10 in diosmin+I/R group was significantly higher than that in I/R group (P<0.01 or P<0.05). CONCLUSION: Diosmin not only decreases the production of TNF-α, IL-1β, IL-6 and IL-8, but also promotes the production of anti-inflammatory cytokine IL-10, suggesting that the protective effect of diosmin on kidney I/R injury was associated with anti-inflammatory mechanism.     

Mechanisms of hypoxia-induced tumor necrosis factor-α production in rat alveolar macrophages

AIM: To study the effect of hypoxia inducible factor-1 alpha (HIF-1α) on tumor necrosis factor alpha (TNF-α) production in rat alveolar macrophages cultured under hypoxic condition. METHODS: Using HIF-1α decoy inhibiting its function, Immunohistochemistry, Western blot, semiquantitative RT-PCR and ELISA were used to determine the expression of HIF-1α protein and mRNA and the production of TNF-α in rat alveolar macrophages cultured under hypoxic condition (3% O2, 5% CO2, 92% N2), respectively. RESULTS: Expression of HIF-1α was positive in cultured macrophage nucleoli in hypoxia group and HIF-1α decoy group but it was negative in nomoxic control group. The content of HIF-1α protein in hypoxia group and HIF-1α decoy group were significantly higher than that in nomoxic control group (P<0.05). The content of HIF-1α mRNA in hypoxia group and HIF-1α decoy group were markedly higher than that in nomoxic control group (P<0.05), respectively. The content of TNF-α in hypoxia group (115±17 ng/L) was higher than that in control group ［（69±13） ng/L, P<0.05］ and HIF-1α decoy group ［（81±15） ng/L, P<0.05］. CONCLUSION: Hypoxia can increase significantly expression and activity of HIF-1α， which can promote the production of TNF-α in rat alveolar macrophages. It suggests that HIF-1α plays an important role in the pathogenesis of chronic inflammation-related diseases that can give rise to lung hypoxia such as COPD.     

Expression of TNF-α in a rat model of chronic Pseudomonas aeruginosa biomembrane associated with lung infection

AIM: To investigate the kinetics of tumor necrosis factor alpha (TNF-α) in an animal model of chronic P. aeruginosa biomembrane associated with lung infection. METHODS: Rats were challenged with 0.1 mL of PAO579 (1012 CFU/L) in alginate beads or 0.1 mL of planktonic PAO579 (1012 CFU/L). After challenging for 3, 7 and 14 d, bacteriological and pathological features, and TNF-α expression in lung tissue were observed. RESULTS: (1) CFU/lung in alginate beads group was significantly higher than that in planktonic bacteria group (P＜0.01, P＜0.01, P＜0.01, respectively). (2) Macroscopic lung pathology and the inflammation in alginate beads group were significantly severer compared to those in planktonic bacteria group. (3) The level of TNF-α in lung tissue in alginate beads group was higher than that in planktonic bacteria group (P＜0.05, P＜0.05, P＜0.05, respectively). Simple regression analysis showed a correlation between the level of TNF-α and macroscopic lung pathology in alginate beads group (r=0.78, P<0.05).CONCLUSION: TNF-α induces lung injury in a rat model of chronic P. aeruginsa biomembrane with lung infection.     

Cytokine levels and the discrepancy of dexamethasone intervening in ALI rats induced by hydrochloric acid and lipopolysaccharide

AIM: To explore the cytokines level and the discrepancy of reaction to dexamethasone (Dex) in ALI rats induced by hydrochloric acid (HCl) and lipopolysaccharide (LPS). METHODS: Ninety-six SD rats were divided into six groups at random (n=16 in each group): NS group, HCl group, LPS group, NS+Dex group, HCl+Dex group and LPS+Dex group. Every group was divided into two subgroups: the bronchoalveolar lavage (BAL) subgroup and no bronchoalveolar lavage (NBAL) subgroup. The total leukocytes, PMN%, macrophage%, lymphocyte%, total protein in BALF and the wet/dry of the lung weight were measured. The concentrations of TNF-α, IL-1β, IL-4 and IL-10 in serum and BALF in every group were compared. RESULTS: (1) In the groups of LPS and HCl, the total leukocytes, PMN numbers, the protein concentration in the BALF and W/D were higher than those in control group (P<0.05). Compared to LPS groups, the percentage of macrophage increased in LPS+Dex group (P<0.05). (2) In serum and BALF of both LPS group and HCl group, the concentrations of TNF-α, IL-4 and IL-10 were higher than those in the control (P<0.01). The content of IL-1β in serum of all the groups was undetected. Compared to LPS groups, the concentrations of TNF-α and that of IL-1β decreased in LPS+Dex group (P<0.05). The concentration of IL-10 in LPS+Dex group was higher than that in LPS group (P<0.01). CONCLUSION: The permeability and the inflammatory cytokines in these two models were not consistent. Glucocorticoids play an effective role for resisting ALI induced by LPS but not HCl.     

Protective effects of hypercapnia on acute lung injury and it's mechanisms

AIM: To investigate whether hypercapnia is protective against acute lung injury (ALI) in a rabbit model, and study it's potential mechanisms. METHODS: Twenty-two healthy New Zealand white rabbits were involved in this study, and randomly allocated to control group (group C), normocapnic group (group N) and hypercapnic group (group H). Oleic acid (0.1 mL/kg) was injected intravenously to establish ALI model. Lung mechanics, hemodynamics, blood-gas analysis, the content of malondialdehyde (MDA) and superoxide dismutase (SOD) activity in lung tissue were measured. Apoptosis was analyzed after 3h mechanical ventilation. RESULTS: (1) Peak airway pressure in group H was significantly lower than that in group N (P<0.05) and the dynamic lung compliance was significantly higher than that in group N (P<0.05). (2) PaO₂ in group H was significantly higher than that in group N(P<0.05). (3) The content of MDA was significantly lower but the activity of SOD was significantly higher in group H than that in group N (P<0.05). (4) Apoptosis index in group H was significantly lower than that in group N (P<0.01). (5) Histologic damage was significantly severer in group N than group H. (6) PaCO₂ was correlated with pH, PaO₂, dynamic lung compliance, peak airway pressure and pulmonary permeability index (r=－0.928, P<0.01; r=0.511, 0.526, -0.506, -0.556, P<0.05, respectively). CONCLUSION: Hypercapnia protects lung from oleic acid-induced injury in rabbits. The mechanisms of protection might be associated with improvement of oxidation/anti-oxidation imbalance and inhibition of apoptosis.     

Antagonistic effect of bilirulin on acute lung injury induced by LPS in rats

AIM: To investigate the effect of bilirubin on acute lung injury (ALI) and the mechanism. METHODS: 30 male Wistar rats were divided into normal group, ALI group and bilirubin treatment group. Lung specimens were examined by histopathological technique. Lung index (LI) and lung permeability index (LPI) were measured. Moreover, white blood cell (WBC) count, neutrophil percentage (PMN%) and the content of protein (Pr) in the bronchoalveolar lavage fluid (BALF), as well as the contents of superoxide dismutase (SOD), malonaldehyde (MDA) and glutathione peroxidase (GSH-Px) in the lung homogenate were determined. RESULTS: (1) In ALI group: LI, WBC count, PMN%, Pr and LPI increased significantly compared with normal group (P<0.01). In bilirubin treatment group, all the values determined decreased compared with ALI group (P<0.01; P<0.05). No notable discrepancy between bilirubin treatment group and normal group (P>0.05) was observed. (2) In ALI group, the content of MDA was significantly higher (P<0.01), but the contents of SOD and GSH-Px were significantly lower than those in normal group (P<0.01). In bilirubin treatment group, the content of MDA decreased significantly (P<0.01) but the contents of SOD and GSH-Px increased significantly (P<0.01; P<0.05) compared with ALI group. No notable discrepancy between bilirubin treatment group and normal group was observed (P>0.05). CONCLUSION: Bilirubin relieves ALI induced by LPS in rats via antioxidation.     

Effects of N-acetylcysteine combined with azithromycin on oxidative stress in rats with chronic obstructive pulmonary disease

AIM: To investigate the effects of N-acetylcysteine (NAC) combined with azithromycin (AZI) on oxidative stress in the rats with chronic obstructive pulmonary disease (COPD). METHODS: Male Wistar rats (n=60) were randomly divided into control group, model group, AZI intervention group,NAC intervention group and AZI+NAC group. The COPD model was established by passive smoking and intratracheal instillation of lipopolysaccharide. Each day 30 min prior to smoking, intragastric administration with AZI, NAC or combination of the 2 drugs was given for AZI, NAC, and AZI+NAC groups, respectively. On the 31st day, all rats were killed following lung function test. Cell counts of bronchoalveolar lavage fluid (BALF) were performed, and the contents of interleukin-8 (IL-8), interleukin-17 (IL-17) and tumor necrosis factor alpha (TNF-α) in BALF were measured by ELISA. The histopathology of the lung tissues was observed under light microscope, and the levels of superoxide dismutase (SOD), glutathione peroxidase (GSH-Px) and malondialdehyde (MDA) in the lung homogenate were measured. RESULTS: Compared with control group, the other 4 groups showed decreased pulmonary function, and inflammatory cell infiltration and alveolar destruction in histopathology. Compared with control group, the other groups showed higher white blood cells, monocyte-macrophages, neutrophils and lymphocytes in the BALF (P<0.05). Compared with model group, AZI group and NAC group, lower white blood cells, neutrophils and lymphocytes in the BALF were observed in AZI+NAC group (P<0.05). Compared with model group, IL-8, IL-17, TNF-α and MDA in AZI group, NAC group and AZI+NAC group significantly decreased (P<0.05), while SOD and GSH-Px significantly increased (P<0.05). Compared with AZI or NAC group, IL-8, IL-17, TNF-α and MDA in AZI+NAC group significantly decreased (P<0.05), while SOD and GSH-Px increased significantly (P<0.05). CONCLUSION: Both NAC and AZI attenuate the lung inflammation and oxidative damage in COPD model rats. Combined medication exerts preferable anti-oxidation effects, which might be more suitable for the treatment of COPD.