Role of sulfur dioxide in acute lung injury induced by ischemia-reperfusion of hind limbs in rats

AIM：To explore the role of endogenous and exogenous sulfur dioxide(SO2) in acute lung injury(ALI) induced by ischemia-reperfusion(IR) of limbs in rats. METHODS：The rat model of ALI was induced by ischemia and reperfusion of the hind limbs using a tourniquet. The rats(n=96) were randomly divided into 6 groups: sham, IR, sham+SO2, sham+hydroxamate(HDX), IR+SO2 and IR+HDX. The morphological changes of the lung tissues were observed under light microscope. Meanwhile, polymorphonuclear neutrophils(PMN) in alveolar septum, lung coefficient, lung levels of malondialdehyde(MDA) and intercellular adhesion molecule(ICAM)-1, serum tumor necrosis factor(TNF)-α and interleukin(IL)-1, the content of SO2 and the activity of aspartate aminotransferase(AST) in the lung tissues, and 24 h survival rate of the rats were measured. RESULTS：IR of the rat limbs resulted in the damage of the lung tissues, and the increases in PMN in alveolar septum, lung coefficient, the lung levels of MDA and ICAM-1 and the serum levels of TNF-α and IL-1 were also observed with the reductions of SO2 content and AST activity. Pretreatment with SO2 donor Na2SO3/NaHSO3 alleviated the changes of the indicators above. HDX, an inhibitor of SO2-producing enzymes, aggravated the changes above. CONCLUSION：Down-regulation of AST/SO2 pathway is involved in the pathogenesis of limb IR-induced ALI. Administration of exogenous SO2 might attenuate lung injury through anti-inflammation and anti-oxidation.     

Effects of neutrophil extracellular traps on acute lung injury in neonatal rats

AIMTo investigate the role of neutrophil extracellular traps (NETs) in neonatal rats with acute lung injury (ALI). METHODSThirty 7-day-old SD rats were randomly divided into normal saline control group, ALI group and ALI+deoxyribonuclease (Dnase) group (each n=10). The rats in ALI group were intraperitoneally injected with lipopolysaccharides (LPS) at 20 mg/kg, and the rats in ALI+Dnase group were intraperitoneally injected with Dnase at 5 mg/kg after LPS injection. After 6 h, the rats were anesthetized with chloral hydrate, bronchial alveolar lavage fluid (BALF) was collected, and the content of cell-free DNA (cf-DNA) in BALF was detected by fluorescence microarray. The right lung tissues were fixed in 4% paraformaldehyde, and the morphological structure of the lung tissues were observed by HE staining. The content of interleukin-6 (IL-6) and tumor necrosis factor-α （TNF-α） in the left lung homogenate was measured by ELISA. Immunofluorescence and Western blot were used to detect the production of citrullinated histone H3 (CitH3) and myeloperoxidase (MPO) in the rat lung tissues. RESULTSCompared with control group, the levels of cf-DNA, CitH3, MPO, IL-6 and TNF-α in lung tissues of neonatal rats in ALI group and ALI+Dnase group were all increased (P<0.05), and severe inflammatory infiltration in the lung tissues was observed. Compared with ALI group, the levels of cf-DNA, CitH3, MPO, IL-6 and TNF-α in ALI+Dnase group were decreased (P<0.05), and the inflammatory infiltration was attenuated. CONCLUSION In neonatal rats with ALI, the level of NETs is an important indicator of lung tissue injury, and NETs may be a new target for the treatment of neonatal ALI.     

Vinpocetine injection attenuates lipopolysaccharide-induced acute lung injury in rats

AIM:To observe the inhibitory effects of vinpocetine injection on lipopolysaccharide (LPS)-induced acute lung injury (ALI) in the rats and to explore the underlying mechanisms.METHODS:Male Wistar rats (n=50) were randomly divided into 5 groups:control group,ALI model group,and low,medium and high doses of vinpocetine treatment groups.The rats in control group were injected with 0.9% NaCl at 5 mL/kg through femoral vein.The rats in ALI model group received LPS at 10 mg/kg through femoral vein.After injected with LPS,the rats in vinpocetine treatment groups received vinpocetine at 0.2 mg/kg,0.7 mg/kg or 1.2 mg/kg via intraperitoneal injection.The pathological changes of the lung tissues were observed under microscope with HE staining.The cell apoptosis in the lung tissues was detected by TUNEL staining.Myeloperoxidase (MPO) activity was measured by the method of spectrophotometry.The protein expression of NF-κB,ICAM-1,VCAM-1,Bax and Bcl-2 was determined by Western blot.RESULTS:Compared with ALI group,administration of vinpocetine significantly attenuated the structural injury of the lung and the infiltration of inflammatory cells.Moreover,vinpocetine decreased cell apoptosis and MPO activity in the lung tissues of ALI rats.In addition,the protein expression of NF-κB,ICAM-1,VCAM-1 and Bax was inhibited after vinpocetin treatment,whereas Bcl-2 expression was increased.CONCLUSION:Vinpocetine attenuates LPS-lung injury by reducing MPO activity and regulating NF-κB,ICAM-1,VCAM-1,Bax and Bcl-2 protein expression.     

Pre-treatment with melatonin inhibits oleic acid-induced acute lung injury in rats

AIM: To assess the protective role of melatonin (MEL) in a rat model of oleic-induced acute lung injury.METHODS: Twenty-four rats were randomly allocated to three groups as follows: saline(NS) injection group, oleic acid(OA) injection group and MEL plus OA injection group, the lavage protein, lung wet-to-dry weight ratio, malondialdehyde(MDA) content, superoxide dismutase(SOD) activity and lung histopathology were examined. RESULTS: (1) Injection 0.15 mL/kg of OA led to a severe acute lung injury(ALI), characterized by significantly increasing in lavage protein, lung coefficient (P<0.01), and by histopathological alterations which presented hemorrhage, edema, thickened alveolar septum and the existence of inflammatory cells in alveolar spaces; (2) Infusion of MEL (20 mg/kg, intraperitoneally for 60 min before the oleic acid) markedly alleviated above-mentioned symptom induced by OA, consistent with decrease of MDA level (P<0.01) and the increase of SOD activty (P<0.01). CONCLUSION: Pre-treatment with MEL can attenuate the OA-induced ALI in rats via cleaning and preventing the formation of free radicals and further lessening the increase of alveolocapillary membrane permeability, these data suggest that MEL may be effective in the prevention of ALI.     

Role of hydrogen sulfide in acute lung injury induced by ischemia-reperfusion of hind limbs in rats

AIM: To explore the role of endogenous and exogenous hydrogen sulfide (H₂S) in acute lung injury (ALI) induced by ischmia-reperfusion (IR) of hind limbs in rats.METHODS: A Sprague-Dawley rat model of acute lung injury was induced by ischemia of the hind limbs for 4 h and reperfusion for another 4 h. The rats (n=120) were randomly divided into 4 groups: control, IR, NaHS (H₂S donor)+IR, and propargylglycine +IR. The animals were sacrificed after reperfusion. Lung weight/body weight ratio (LW/BW) was measured and calculated. Morphological changes of the lung tissues were observed. The concentrations of H₂S, nitric oxide (NO) and carbon monoxide (CO) in plasma were tested. The content of malondialdehyde (MDA), the activity of CSE, inducible nitric oxide synthase (iNOS) and hemeoxygenase (HO) in the lungs were determined. The polymorpho-nuclear neutrophils(PMN) and protein content in bronchoalveolar lavage fluid(BALF) were also measured. The correlation of H₂S content with the above indices was analyzed.RESULTS: Compared with control group, severe injuries of the lung tissues, raised LW/BW, MDA concentration, PMN and protein contents in BALF were observed in IR group. Limb IR also made a drop in the concentration of plasma H₂S and the activity of lung CSE, while the activity of iNOS and HO in the lung tissues and the levels of plasma NO and CO increased. Administration of NaHS before IR attenuated the changes induced by IR, while pre-administration of PPG exacerbated the IR injuries and increased the plasma NO level and lung iNOS activity. The H₂S content was positively correlated with CSE activity, CO content and HO-1 activity (P<0.01), and negatively correlated with the other indices (P<0.01).CONCLUSION: Down-regulation of H₂S/CSE is involved in the pathogenesis of acute lung injury induced by IR. Endogenous and exogenous H₂S protects against lung injuries. The anti-injury effects of H₂S are related with its anti-oxidative activity to attenuate the inflammatory over-reactions in the lung induced by PMN. Down-regulation of NO/iNOS system and up-regulation of CO/HO-1 system by H₂S are also involved in the process of anti-injury to ALI.     

An animal model of acute lung injury induced by left ventricular ischemia-reperfusion

AIM: To establish a method of making acute lung injury model induced by left ventricular ischemia-reperfusion.METHODS: Forty New Zealand rabbits were randomly divided into model group (MG) and control group (CG). The left ventricular ischemia-reperfusion was established by ligaturing and loosing the anterior descending branch of the left coronary artery in the rabbits in MG group. The electrocardiogram, the phrenic nerve discharge curve, the ultrastructure and histological analysis of the lung tissues were compared between MG group and CG group.RESULTS: The myocardial ischemia-reperfusion injury resulted in acute lung injury in the rabbits of MG group, and the duration and amplitude of the phrenic nerve discharge curve were reduced. The ultrastructure and histological analysis of the lung tissues in MG group showed acute injury. These situations were not appeared in CG group. The correlation between myocardial ischemia-reperfusion injury and acute lung injury were significant in MG group. CONCLUSION: The animal model of acute lung injury induced by left ventricular ischemia-reperfusion is reliable and feasible.     

Role of heme oxygenase in cholecystokinin octopeptide ameliorating acute lung injury induced by lipopolysaccharide

AIM: To study the role of heme oxygenase (HO)-1 in the mechanism of cholecystokinin-octapeptide (CCK-8) for attenuation of acute lung injury (ALI) induced by lipopolysaccharide (LPS).METHODS: Adult male rats were randomly divided into five groups: control group,LPS group,CCK-8+LPS group,LPS+ Hm (hemin,HO-1 donor) group and LPS+ZnPP (zinc protoporphyrin,specific inhibitor of HO-1) group.PMN number in bronchoalveolar lavage fluid (BALF),the structure of the lung,MDA content,HO-1 activity,the expressions of HO-1 mRNA and protein in the lung were detected respectively.RESULTS: The lung injury in LPS group was observed,at the same time the numbers of PMN,the content of MDA,the activity and the expression of HO-1 were all higher than those in control group (all P<0.05).The degree of lung injury,PMN numbers and MDA content were lower,while the activity and the expression of HO-1 in CCK-8+LPS and LPS+Hm group were higher than those in LPS group (all P<0.05).However,the degree of lung injury,PMN numbers and MDA content were higher,the activity and the expression of HO-1 were lower in LPS+ZnPP than those in LPS group respectively (all P<0.05).CONCLUSION: CCK-8 attenuates the LPS-induced ALI by means of anti-oxidation and inhibits PMN aggregation,which are both mediated by HO-1 partly.     

Protective role of endogenous hydrogen sulfide in cholecystokinin octapeptid against acute lung injury induced by lipopolysaccharide

AIM: To explore the role of endogenous hydrogen sulfide (H₂S) in the mechanism of cholecystokinin octapeptide (CCK-8) to alleviate acute lung injury (ALI) induced by lipopolysaccharide (LPS). METHODS: Eighty-four Sprague-Dawley rats were randomly divided into seven groups: control, LPS (instilled intratracheally to reproduce the model of ALI), NaHS (H₂S donor) +LPS, propargylglycine ［inhibitor of cysathionine-γ-lyase (CSE), PPG］+LPS, CCK-8+LPS, PPG+CCK-8+LPS and CCK-8 group. Animals were sacrificed at 4 h and 8 h after agent instillation. The wet and dry ratio (W/D) of the lung weight was measured and calculated. Morphological changes of lung tissues were observed. H₂S concentration in plasma, malondialdehyde (MDA) content, myeloperoxidase (MPO) and CSE activities in the lung were determined. Furthermore, the level of P-selectin of lung tissue was measured by radioimmunoassay, the CSE mRNA expression in the lung was detected by RT-PCR, and the protein content in bronchoalveolar lavage fluid (BALF) was detected. RESULTS: Compared with control, severe injury of lung tissues and increase in W/D, protein content in BALF, MDA content, MPO activity and P-selectin level in the lung were observed in rats treated with LPS. LPS also lead to a drop in plasma H₂S concentration, lung CSE activity and CSE mRNA expression. Administration of NaHS before LPS could attenuate the changes induced by LPS, while H₂S concentration, CSE activity and CSE mRNA expression were higher than those in LPS group. However, pre-treatment with PPG exacerbated the lung injury induced by LPS, H₂S concentration, CSE activity and CSE mRNA expression were lower than those in LPS and CCK-8 +LPS group, respectively. CONCLUSION: CCK-8 attenuates LPS-induced acute lung injury by means of anti-oxidation and inhibition of PMN adhesion and aggregation, both of which are mediated by endogenous H₂S.     

Porcine surfactant in treatment of LPS-induced early-stage acute lung injury in rats

AIM: To evaluate the therapeutic efficacy of intratracheal instillation of porcine pulmonary surfactant (PPS) in rats with lipopolysaccharides (LPS)-induced early-stage ALI in this study.METHODS: SD rats weighing 200 g-300 g were randomly divided into 4 groups: LPS (1.5 mg·kg-1)+saline,LPS+PPS 100 mg·kg^-1,LPS+PPS 150 mg·kg^-1,LPS+PPS 200 mg·kg^-1.The PaO₂ and PaCO₂,as well as survival rate of rats were examined for 6 h after the start of PPS-instillation.Then,rats were killed and lungs were immediately removed for lung index (LI) and histological analysis.The bronchoalveolar lavage fluid (BALF) was collected for measurement of total protein (TP) contents,TNF-α level and white blood cell(WBC) numbers.RESULTS: Significantly increased PaO₂,reduced mortality rate,decreased total protein and TNF-α contents in BAL,as well as lung index and meliorated histological appearance were observed in three PPS-treated groups compared with group given saline after LPS (P<0.05).The therapeutic effect in PPS150 and PPS200 groups was better than that in PPS100 group.CONCLUSION: Intratracheal PPS instillation provides protective effect on acute lung injury in rats induced by LPS.     

Protective effect of dexmedetomidine-ulinastatin combination on lipopolysaccharide-induced acute lung injury in rats

AIM：To investigate the effects of dexmedetomidine-ulinastatin combination on acute lung injury induced by lipopolysaccharide (LPS) in rats. METHODS：Male Wistar rats were randomly divided into 5 groups: saline control group (NS group) was given saline (5 mL/kg, iv) alone; LPS group (L group) was given LPS (10 mg/kg, over 10 min); dexmedetomidine+LPS group (L+D group) was treated with the additional administration of dexmedetomidine (1 μg·kg -1·h -1) immediately after LPS injection; ulinastatin+LPS group (L+U group) was treated with the addi-tional administration of ulinastatin (50 000 U/kg, ip) immediately after LPS injection; dexmedetomidine+ulinastatin+LPS group (L+D+U group) received dexmedetomidine (1 μg·kg -1·h -1) and ulinastatin (50 000 U/kg) immediately after LPS injection. The animals were sacrificed at 6 h after LPS or NS administration. Partial pressure of arterial oxygen (PaO 2), pH and base excess (BE) were measured, and the lungs were removed for evaluation of histological characteristics and determining the concentrations of TNF-α, IL-1β, macrophage inflammatory protein 2 (MIP-2), malondialdehyde (MDA), nitric oxide (NO), prostaglandin E 2 (PGE 2) and myeloperoxidase (MPO) in lung tissues, lung wet/dry weight ratio (W/D), and albumin in brochoalveolar lavage fluid (BLAF). The pulmonary expression of nuclear factor kappa B (NF-κB) p65 was evaluated by Western blotting. RESULTS：Compared with NS group, PaO 2, pH and BE was lower in L group, which was increased by treatment with dexmedetomidine-ulinastatin combination but not by dexmedetomidine or ulinastatin alone. Compared with NS group, LPS induced marked lung histological injury, which was less pronounced in the animals treated with dexmedetomidine-ulinastatin combination but not dexmedetomidine or ulinastatin alone. The levels of IL-1β, IL-6, MIP-2, MDA, NO and PGE 2 in the lung tissues increased in L group compared with NS group, which were reduced by dexmedetomidine-ulinastatin combination but not by dexmedetomidine or ulinastatin alone. The MPO activity, MDA level and W/D increased in the lung tissues in L group compared with NS group, which was reduced by dexmedetomidine-ulinastatin combination but not by dexmedetomidine or ulinastatin alone. Compared with NS group, the albumin concentration in the BLAF increased, which was reduced by dexmedetomidine-ulinastatin combination but not by dexmedetomidine or ulinastatin alone. Compared with NS group, the expression of NF-κB p65 increased in L group, which was reduced by dexmedetomidine-ulinastatin combination but not by dexmedetomidine or ulinastatin alone.CONCLUSION：Dexmedetomidine-ulinastatin combination has a protective effect on LPS-induced acute lung injury in the rats.     

Protective effect of Auricularia auricular-judae polysaccharide on pulmonary tissues of rats with LPS-induced acute lung injury

AIM: To investigate the effects of Auricularia auricular-judae polysaccharide(AAP) on pulmonary tissues of rats with LPS-induced acute lung injury(ALI) and its mechanisms.METHODS: Adult Sprague-Dawley rats were randomly divided into control group, LPS group,low-dose AAP group, middle-dose AAP group, high-dose APP group, and dexamethasone group. The rats were injected with LPS(8 mg/kg, ip) to induce ALI. The rats in the AAP groups were treated with AAP for 7 d before the induction of ALI. The protein concentration in the bronchoalveolar lavage fluid(BALF) was measured. The lung edema degree was measured by detecting the wet/dry weight ratio. The myeloper-oxidase(MPO), total antioxidant capacity(T-AOC), total superoxide dismutase(T-SOD), nitric oxide synthase(NOS) and malondialdehyde(MDA) levels were determined. The pathological changes of the lung tissues were evaluated by HE staining.RESULTS: Treatment with AAP significantly improved LPS-induced lung pathological changes, attenuated the protein concentration in the BALF and wet/dry weight ratio, inhibited the activities of MPO and NOS, reduced MDA level and increased the activities of T-AOC and T-SOD.CONCLUSION: AAP protects against LPS-induced acute lung injury in rats.     

Protective effect of recombinant human serum albumin-thioredoxin fusion protein on mice with acute lung injury induced by influenza virus

AIM To investigate the protective effect of recombinant human serum albumin (HSA)-thioredox?in (Trx) fusion protein (HSA-Trx) on mice with acute lung injury (ALI) induced by influenza virus infection. METH?ODS: The recombinant HAS-Trx fusion protein was generated by Pichia pastoris expression system. ICR mice were used to establish the animal model of ALI induced by PR8 (H1N1) influenza virus, and the experimental mice were divided into healthy control group, ALI group, ALI+Trx group and ALI+HSA-Trx group, with 10 mice in each group. The bronchoalveolar lavage fluid (BALF) in each group was collected, the total number of cells and the number of alveolar neutrophils were determined, the protein concentration was measured by Coomassie brilliant blue solution method, and the interferon-γ (IFN-γ) content in BALF was detected by ELISA. The lung tissues were collected for hematoxylin and eosin staining. The inducible nitric oxide synthase (iNOS), 8-hydroxydeoxyguanosine (8-OHdG) and 3-nitrotyrosine (NO₂-Tyr) in lung tissues were detected by immunofluorescence method. Peroxide concentration in plasma was evaluated using a CR2000RC analyzer. RESULTS HSA-Trx treatment significantly reduced the total number of cells, neutrophils and total protein in BALF of ALI mice (P<0.05), and decreased the levels of 8-OHdG, NO₂-Tyr in lung tissue and peroxide in plasma (P<0.05). However, it has no significant inhibitory effect on iNOS and IFN-γ expression (P>0.05). CONCLUSION HSA-Trx inhibits inflammatory response and excessive production of nitric oxide in the lung, thus protecting influ?enza virus-induced ALI mice.     

Protective effect of N-acetylcysteine on mice with acute lung injury induced by H9N2 swine influenza virus

AIM: To investigate the effects of N-acetylcysteine (NAC) on acute lung injury induced by H9N2 swine influenza virus (SIV) in mice. METHODS: BALB/c mice were used to establish the animal model of acute lung injury by nasal inoculation of H9N2 SIV. The mice were divided into control group (without SIV infection), H9N2 SIV group (inoculation of H9N2 SIV) and NAC group (inoculation of H9N2 SIV plus pretreatment with NAC). The pulmonary edema was evaluated by determining the lung wet weight/dry weight (W/D) ratio. The pathological changes of the lung tissues were observed. The concontrations of TNF-α, IL-1β and IL-6 in bronchoalveolar lavage fluid (BALF) were measured.The virus titer, T-SOD activity, MPO activity and MDA content in the homogenate of the lung tissues were detected. RESULTS: Treatment with NAC decreased the morality of infected mice, and significantly prolonged the survival time of infected mice. The pathological changes of the lung tissues, the lung W/D ratio and the lung index were relieved when SIV infected the mice treated with NAC. Treatment with NAC significantly decreased the infiltration of inflammatory cells including macrophages, lymphocytes and neutrophils in the BALF. The levels of TNF-α, IL-6, IL-1β and MDA and the activity of MPO were also decreased. Treatment with NAC also significantly increased the T-SOD activity. CONCLUSION: The protective effect of NAC on the acute lung injury mouse model is related to suppression of the oxidative stress and inflammatory responses.     

Effects of different ventilation strategies on gas exchange and extravascular lung water during early stage of acute lung injury in a canine model

AIM: To evaluate the effects of different ventilation strategies on gas exchange and extravascular lung water during early stage of acute lung injury (ALI). METHODS: Upon the establishment of oleic acid-induced ALI (diagnostic standard: PaO₂/FiO₂ ≤ 300 mmHg), 24 adult mongrel dogs were randomly divided into 3 groups (n=8 each) according to different ventilation strategies: controlling high-concentration oxygen therapy (O₂) group, continuous positive airway pressure (CPAP) group and bi-level positive airway pressure (BiPAP) group. The parameters of gas exchange and hemodynamics including the values of normal baseline, at ALI early stage (positive control) and from 1 to 4 h after treatment were recorded continuously. RESULTS: Compared with the value at the beginning of ALI, after 4 h of artificial ventilation, the improvement in oxygenation index (PaO₂/FiO₂) in BiPAP group (375.83±81.55, P<0.01) and CPAP group (327.17±78.82, P<0.01) were better than that in O₂ group (255.00±49.85, P>0.05). The ratio of alveolar dead space to tidal volume [V_D(alv)/V_T]in O₂ group further increased (P<0.01), while it obviously declined in CPAP group and BiPAP group (P<0.01). Oxygen delivery (DO₂) in BiPAP group (P<0.01) was much higher than that in CPAP group and O₂ group, while oxygen consumption (VO₂) and oxygen extraction rate (O₂ER) in O₂ group were evidently higher than those in CPAP group and BiPAP group (P<0.05, P<0.01). After treatment, the alveolar-arterial oxygen differences [P_(A-a)O₂] of the 3 ventilation groups were significantly higher than the normal baseline values and the values at early ALI stage (P<0.01). BiPAP and CPAP greatly reduced the ratio of shunted blood to total perfusion (Qs/Qt) as compared with O₂ group (P<0.01). Some parameters including pulmonary arterial wedge pressure (PAWP) and index of cardiac output (CI) kept stable, while mean pulmonary arterial pressure (MPAP) and pulmonary vascular resistance index (PVRI) further increased in CPAP group and BiPAP group (P<0.05,P<0.01). Three ventilation strategies did not effectively control the increase in extravascular lung water index (ELWI). CONCLUSION: During early stage of ALI, BiPAP and CPAP make active effects on improving gas exchange and tissue oxygenation. BiPAP displays more significant therapeutic effect than CPAP and oxygen therapy. The 3 ventilation strategies have no obvious effects on reducing extravascular lung water.     

Effects of caveolin-1 scaffolding domain peptide on LPS-induced acute lung injury in mice

AIM: To investigate the effects of caveolin-1 (Cav-1) scaffolding domain peptide, cavtratin, on lipopolysaccharide (LPS)-induced mouse acute lung injury and heme oxygenase-1 (HO-1) activity. METHODS: Adult male BALB/c mice were randomly divided into 6 groups (n=8 to 10):control, Antennapedia internalization sequence (AP), LPS, LPS+hemin, LPS+ hemin+cavtratin and LPS+hemin+cavtratin+zinc protoporphyrin IX (ZnPP) groups. After LPS administration for 24 h, the lung pathological changes, the wet/dry weight (W/D) ratio of lung tissues, total cell number in bronchoalveolar lavage fluid and serum lactate dehydrogenase activity were measured. The co-localization of HO-1 and Cav-1 was displayed by immunofluorescence, and the HO-1 activity were detected. The mRNA expression of pro-inflammatory cytokines IL-1β, IL-6, TNF-α, MCP-1 and iNOS was detected by real-time PCR. RESULTS: The mice in LPS+hemin+cavtratin group had the decreased interaction between HO-1 and Cav-1, and the increased HO-1 activity compare with LPS group (P<0.05). Compared with LPS group, the pulmonary damage was attenuated in LPS+hemin+cavtratin group, and the injury indexes, including W/D ratio, total cell number in bronchoalveolar lavage fluid and lactate dehydrogenase activity in the serum, and the mRNA expression of inflammatory cytokines all decreased (P<0.05). HO-1 activity inhibitor ZnPP abolished the above protective effect of cavtratin on the lung tissues with LPS-induced acute lung injury. CONCLUSION: Cavtratin has beneficial effects on the lung with LPS-induced acute injury by restoring the HO-1 activity.     

Apoptosis of hepatocytes induced by acute kidney injury in rats

AIM: To observe the cytological changes of hepatocytes undergoing apoptosis induced by acute kidney injury (AKI) in rats. METHODS: The rat models of AKI, including ischemic and non-ischemic AKI, were established. Western blotting, immunohistochemical staining, light and electron microscopy were used in this study. RESULTS: Cellular necrosis in renal tubules, as the basic morphological changes of ischemic AKI, and renal tubular cells undergoing apoptosis were evident in ischemic AKI. Meanwhile, tumor necrosis facotor receptor α (TNFRα) and caspase-3 was strongly expressed in the livers from AKI rats. Caspase-3-positive cells were evident in the livers from AKI rats. Microscopic examinations revealed that hepatocytes undergoing apoptosis and para-apoptosis were observed in damaged livers of both ischemic and non-ischemic AKI animals. No significant difference of hepatic apoptosis between ischemic and non-ischemic AKI animals was observed. CONCLUSION: Either apoptosis, caspase-dependent cell death or para-apoptosis are involved in hepatic injury induced by AKI. TNFRα initiation and cleaved caspase family are the pathways of hepatocytes undergoing apoptosis induced by AKI.     

Effects of oxidative stress and inflammatory response on kidney injury in mice with hyperthyroidism

AIM To explore the effects of oxidative stress and inflammatory response on kidney injury induced by hyperthyroidism in mice. METHODS Forty male Kunming mice were randomly divided into control group （n=20） and L-thyroxine （T4） group （n=20）. The mice in T4 group were intraperitoneally injected with T4 diluent at a dose of 1 mg/kg to induce hyperthyroidism, and those in control group were injected with normal saline of the same volume. After 7 weeks, the mice were weighed and dissected, the kidneys were removed and weighed, and the length of tibia was also measured. The activity of superoxide dismutase （SOD） and the content of malondialdehyde （MDA） in the kidney tissues were detected. The pathological changes of the kidney tissues were observed by HE staining. The levels of 4-hydroxynonenal （4-HNE）-modified proteins, interleukin-1 receptor-associated kinase 1 （IRAK1） and tumor necrosis factor receptor-related factor 6 （TRAF6） were determined by Western blot and immunohistochemistry. RESULTS Compared with control group, the body weight of the mice was decreased, while the kidney size and weight were increased significantly in T4 group. In addition, the ratios of kidney weight/body weight and kidney weight/tibia length were also increased （P<0.05）. In T4 group, the renal tubules were enlarged, and the epithelial cells of renal tubules were swollen and exfoliated, with vacuolar degeneration. Furthermore, reduced SOD activity, and increased MDA content and 4-HNE-modified proteins were found in T4 group, all of which were related to oxidative stress （P<0.05）. The levels of inflammation-related proteins IRAK1 and TRAF6 were significantly increased in T4 group （P<0.05）. CONCLUSION Excessive T4 may lead to kidney hypertrophy and injury in mice, and the mechanism may be related to oxidative stress and inflammatory response.     

Effects of ambroxol combined with low-dose heparin on production of ICAM-1 and E,P-selectin in acute lung injury

AIM: To study the production of intercellular adhesion molecule-1(ICAM-1), E-selectin and P-selectin in serum, lung tissues and bronchoalveolar lavage fluid(BALF)of acute lung injury(ALI) model and to observe the effects of ambroxol combined with low-dose heparin on the changes of the 3 factors above.METHODS: Twenty-four healthy rabbits were randomly divided into 3 groups: normal saline control group (NC), oleic acid injury group (OA), ambroxol+ heparin treatment group (AH). The rabbit ALI model was induced by oleic acid injection through auricular vein. Partial pressure of O₂ in artery(PaO₂) was analyzed.The concentrations of ICAM-1 and E-selectin were detected by ELISA.The apoptosis index(AI) was measured by TUNEL method.The expression of P-selectin was determined by immunohistochemical method.The ultrastructural changes of the lung tissues were observed under electron microscope, and the lung wet/dry ratio(W/D) was calculated.RESULTS: PaO₂ in AH group and OA group was significantly lower (P<0.01) than that in NC group, and PaO₂ in AH group was significantly higher than that in OA group (P<0.01). The concentrations of ICAM-1 and E-selectin in serum, lung tissues and BALF, and AI and W/D in lung tissues in AH group were higher (P<0.05 or P<0.01) than those in NC group, and was lower than those in OA group (P<0.05 or P<0.01). In NC group, no significant change of the above parameters at all time points was observed (P>0.05). In OA group, PaO₂ was significantly decreased (P<0.01) with the pathological process developed, and the concentrations of ICAM-1 and E-selectin were significantly increased. In AH group, PaO₂ was decreased (P<0.05),and the concentrations of ICAM-1 and E-selectin were increased with the process of ALI developed. The P-selectin expression in lung tissues of OA group was distributed mainly in inflammatory cells, capillary endothelial cells and plasma. From low to high levels, the order was NC group < AH group < OA group in the expression of P-selectin. The most obvious apoptosis was observed in OA group. No apoptosis or occasional positive cells were found in NC group. The apoptotic rate in AH group was significantly reduced compared with that in OA group.CONCLUSION: In ALI induced by OA, ICAM-1, E-selectin and P-selectin are significantly increased and are involved in the occurrence and development of ALI. Ambroxol combined with low-dose heparin reduces the levels of ICAM-1, E-selectin and P-selectin, the pulmonary edema and the lung injury, improves pulmonary functions, and plays an important role in the prevention and treatment of acute lung injury.