Lung Water Content Research Articles

Comparison of Equivolume, Equiosmolar Solutions of Mannitol and Hypertonic Saline with or without Furosemide on Brain Water Content in Normal Rats

Mannitol and hypertonic saline (HS) are used by clinicians to reduce brain water and intracranial pressure and have been evaluated in a variety of experimental and clinical protocols. Administering equivolume, equiosmolar solutions in healthy animals could help produce fundamental data on water translocation in uninjured tissue. Furthermore, the role of furosemide as an adjunct to osmotherapy remains unclear. Two hundred twenty isoflurane-anesthetized rats were assigned randomly to receive equivolume normal saline, 4.2% HS (1,368 mOsm/L 25% mannitol (1,375 mOsm/L), normal saline plus furosemide (8 mg/kg), or 4.2% HS plus furosemide (8 mg/kg) over 45 min. Rats were killed at 1, 2, 3, and 5 h after completion of the primary infusion. Outcome measurements included body weight; urinary output; serum and urinary osmolarity and electrolytes; and brain, lung, skeletal muscle, and small bowel water content. In the mannitol group, the mean water content of brain tissue during the experiment was 78.0% (99.3% CI, 77.9-78.2%), compared to results from the normal saline (79.3% [99.3% CI, 79.1-79.5%]) and HS (78.8% [99.3% CI, 78.6-78.9%]) groups (P < 0.001), whereas HS plus furosemide yielded 78.0% (99.3% CI, 77.8-78.2%) (P = 0.917). After reaching a nadir at 1 h, brain water content increased at similar rates for mannitol (0.27%/h [99.3% CI, 0.14-0.40%/h]) and HS (0.27%/h [99.3% CI, 0.17-0.37%/h]) groups (P = 0.968). When compared to equivolume, equiosmolar administration of HS, mannitol reduced brain water content to a greater extent over the entire course of the 5-h experiment. When furosemide was added to HS, the brain-dehydrating effect could not be distinguished from that of mannitol.

Sodium Hydrosulphide Alleviates Remote Lung Injury Following Limb Traumatic Injury in Rats

Hydrogen sulphide (H2S) was found to attenuate ventilator or oleic acid induced lung injury. The aim of this study was to explore the effects of exogenous H2S donor, sodium Hydrosulphide (NaHS), on lung injury following blast limb trauma and the underlying mechanisms. For in vitro experiments, pulmonary micro-vessel endothelial cells (PMVECs) were cultured and treated with NaHS or vehicle in the presence of TNF-α. For in vivo, blast limb traumatic rats, induced by using chartaceous electricity detonators, were randomly treated with NaHS, cystathionine gamma-lyase inhibitor (PAG) or vehicle. In vitro, NaHS (100 µM) treatment increased PMVECs viability and decreased LDH release into culture media after tumor necrosis factor (TNF) α challenge. In addition, NaHS treatment prevented the increase of nitric oxide, Intercellular Adhesion Molecule 1(ICAM-1) and interleukin (IL)-6 production and inducible nitric oxide synthase activation induced by TNF-α. Knock-down of NF-E2-Related Factor 2 (Nrf2) partially abolished the protective effect of NaHS. In vivo, NaHS treatment significantly alleviated lung injury following blast limb trauma, demonstrated by a decreased histopathological score and lung water content. Furthermore, NaHS treatment reversed the decrease of H2S concentration in plasma, prevented the increase of TNF-α, IL-6, malondialdehyde and myeloperoxidase, increased the Nrf2 downstream effector glutathione in both plasma and lungs, and reversed the decrease of superoxide dismutase in both plasma and lungs induced by blast limb trauma. Our data indicated that NaHS protects against lung injury following blast limb trauma which is likely associated with suppression of the inflammatory and oxidative response and activation of Nrf2 cellular signal.

Sinomenine Protects against Lipopolysaccharide-Induced Acute Lung Injury in Mice via Adenosine A2A Receptor Signaling

Sinomenine (SIN) is a bioactive alkaloid extracted from the Chinese medicinal plant Sinomenium acutum, which is widely used in the clinical treatment of rheumatoid arthritis (RA). However, its role in acute lung injury (ALI) is unclear. In this study, we investigate the role of SIN in lipopolysaccharide (LPS)-induced ALI in mice. After ALI, lung water content and histological signs of pulmonary injury were attenuated, whereas the PaO2/FIO2 (P/F) ratios were elevated significantly in the mice pretreated with SIN. Additionally, SIN markedly inhibited inflammatory cytokine TNF-α and IL-1β expression levels as well as neutrophil infiltration in the lung tissues of the mice. Microarray analysis and real-time PCR showed that SIN treatment upregulated adenosine A2A receptor (A2AR) expression, and the protective effect of SIN was abolished in A2AR knockout mice. Further investigation in isolated mouse neutrophils confirmed the upregulation of A2AR by SIN and showed that A2AR-cAMP-PKA signaling was involved in the anti-inflammatory effect of SIN. Taken together, these findings demonstrate an A2AR-associated anti-inflammatory effect and the protective role of SIN in ALI, which suggests a potential novel approach to treat ALI.

Effect of Phenylephrine on Alveolar Fluid Clearance in Ventilator-induced Lung Injury

To investigate the effect of phenylephrine (an α-adrenergic agonist) on alveolar fluid clearance (AFC) in ventilator-induced lung injury and the possible mechanism involved. A total of 170 male Wistar rats were randomly allocated into 17 groups (n=10) using random number tables. Short-term (40 minutes) mechanical ventilation with high tidal volume (HVT) was performed to induce lung injury, impair active Na+ transport and lung liquid clearance in the rats. Unventilated rats served as controls. To demonstrate the effect of phenylephrine on AFC, phenylephrine at different concentrations (1×10(-5), 1×10(-6), 1×10(-7), 1×10(-8), and 1×10(-9) mol/L) was injected into the alveolar space of the HVT ventilated rats. To identify the influence of adrenergic antagonists, Na(+) channel, and microtubular system on the effect of phenylephrine, phenylephrine at 1×10(-5) mol/L combined with prazosin (an α1-adrenergic antagonist, 1×10(-4) mol/L), yohimbine (an α2-adrenergic antagonist, 1×10(-4) mol/L), atenolol (a β1- adrenergic antagonist, 1×10(-5) mol/L), ICI-118551 (an β2-adrenergic antagonist, 1×10(-5) mol/L), amiloride (a Na+ channel blocker, 5×10(-4) mol/L), ouabain (a Na(+)/K(+)-ATPase blocker, 5×10(-4) mol/L), colchicine (a microtubular disrupting agent, 0.25 mg/100 g body weight), or β-lumicolchicine (an isomer of colchicine, 0.25 mg/100 g body weight) were perfused into the alveolar space of the rats ventilated with HVT for 40 minutes. AFC and total lung water content were measured. Basal AFC in control rats was (17.47±2.56)%/hour, which decreased to (9.64± 1.32)%/hour in HVT ventilated rats (P=0.003). The perfusion of phenylephrine at 1×10(-8), 1×10(-7), 1×10(-6), and 1×10(-5) mol/L significantly increased the AFC in HVT ventilated rats (all P<0.05). This effect of phenylephrine on AFC was suppressed by prazosin, atenolol, and ICI-118551 in HVT ventilated rats by 53%, 31%, and 37%, respectively (all P<0.05). The AFC-stimulating effect of phenylephrine was lowered by 33% and 42% with amiloride and ouabain, respectively (both P<0.05). Colchicine significantly inhibited the effect of phenylephrine (P=0.031). Phenylephrine could increase the AFC in HVT-ventilated rats and accelerate the absorption of pulmonary edema.

Knockdown of myeloid differentiation protein-2 reduces acute lung injury following orthotopic autologous liver transplantation in a rat model

BackgroundAcute lung injury (ALI) is a serious complication that commonly occurs during orthotopic liver transplantation (OLT). Toll-like receptor 2/4 (TLR2/4) are the main membrane receptors that respond to inflammatory stimuli and mediate NF-kappa B (NF-κB) signal pathway. We previously showed that TLR2/4 expression on monocytes and serum cytokine levels were increased in patients with ALI induced by OLT. Myeloid differentiation protein-2 (MD-2) expresses the functional domains that combines TLRs and play a key regulatory role in TLRs activation. Therefore, we hypothesized that blocking MD-2 would inhibit the TLR2/4-mediated inflammatory response and lessen ALI induced by liver transplantation. MethodThirty-two Sprague Dawley (SD) rats were randomly divided into four groups. One group received a sham operation (Group S), and the other three groups underwent orthotopic autologous liver transplantation (OALT) 48 h after intratracheal administration of saline (Model group; Group M), non-targeting siRNA (negative siRNA control group; Group NC) or siRNA against MD-2 (intervention group; Group RNAi). Lung pathology, lung water content, PaO2, and expression levels of MD-2, TLR2/4, NF-κB, TNF-α, IL-1β and IL-6 were assessed 8 h after OALT. ResultsIn Groups M and NC, OALT produced marked lung pathology with decreased PaO2 levels and increased MD-2, TLR2/4 gene and protein expression levels. Furthermore, the nuclear translocation of the NF-κB P65 subunit, was increased, as were lung concentrations of TNF-α, IL-1β and IL-6. The pathology of ALI and the severity of the above biochemical changes induced by OALT were significantly reduced in the group treated with MD-2 siRNA. ConclusionMD-2 gene knock-down attenuated the increase in TLR2/4 activation and reduced ALI after OALT.

Microwave Stethoscope: Development and Benchmarking of a Vital Signs Sensor Using Computer-Controlled Phantoms and Human Studies

This paper describes a new microwave-based method and associated measurement system for monitoring multiple vital signs (VS) as well as the changes in lung water content. The measurement procedure utilizes a single microwave sensor for reflection coefficient measurements, hence the name "microwave stethoscope (MiSt)," as opposed to the two-sensor transmission method previously proposed by the authors. To compensate for the reduced sensitivity due to reflection coefficient measurements, an improved microwave sensor design with enhanced matching to the skin and broadband operation, as well as an advanced digital signal processing algorithm are used in developing the MiSt. Results from phantom experiments and human clinical trials are described. The results clearly demonstrate that MiSt provides reliable monitoring of multiple VS such as the respiration rate, heart rate, and the changes in lung water content through a single microwave measurement. In addition, information such as heart waveforms that correlates well with electrocardiogram is observed from these microwave measurements. Details of the broadband sensor design, experimental procedure, DSP algorithms used for VS extraction, and obtained results are presented and discussed.

Intratracheal Antitumor Necrosis Factor‐α Antibody Attenuates Lung Tissue Damage Following Cardiopulmonary Bypass

The aim of this study is to investigate the protective effect and underlying mechanism of antitumor necrosis factor-α antibody (TNF-α Ab) on lung tissue injury after cardiopulmonary bypass (CPB). Twenty-eight healthy New Zealand white rabbits were randomly divided into four groups. Group I received only an open chest operation. Groups II-IV all received CPB. Furthermore, groups III and IV received post-CPB endotracheal intubation with phosphate buffered saline or TNF-α Ab (2400 pg/kg), respectively. Perioperative blood neutrophil count, TNF-α level, and malondialdehyde (MDA) levels were determined in both the right and left atriums. Lung water content, TNF-α messenger RNA, protein, apoptosis in situ, and pathomorphological changes were also measured. The results show that TNF-α Ab can significantly inhibit leukocyte accumulation, reduce secretion of TNF-α and MDA, decrease lung tissue apoptosis, and attenuate post-CPB pathomorphological changes. TNF-α Ab administration, however, cannot suppress the expression of TNF-α, suggesting that the protective effects of TNF-α Ab originate from inhibiting the numerous biological functions of TNF-α. Intratracheal TNF-α Ab administration demonstrates a notable protective effect against lung injury after CPB.

Ulinastatin Suppresses Burn-Induced Lipid Peroxidation and Reduces Fluid Requirements in a Swine Model

Objective. Lipid peroxidation plays a critical role in burn-induced plasma leakage, and ulinastatin has been reported to reduce lipid peroxidation in various models. This study aims to examine whether ulinastatin reduces fluid requirements through inhibition of lipid peroxidation in a swine burn model. Methods. Forty miniature swine were subjected to 40% TBSA burns and were randomly allocated to the following four groups: immediate lactated Ringer's resuscitation (ILR), immediate LR containing ulinastatin (ILR/ULI), delayed LR resuscitation (DLR), and delayed LR containing ulinastatin (DLR/ULI). Hemodynamic variables, net fluid accumulation, and plasma thiobarbituric acid reactive substances (TBARS) concentrations were measured. Heart, liver, lung, skeletal muscle, and ileum were harvested at 48 hours after burn for evaluation of TBARS concentrations, activities of antioxidant enzymes, and tissue water content. Results. Ulinastatin significantly reduced pulmonary vascular permeability index (PVPI) and extravascular lung water index (ELWI), net fluid accumulation, and water content of heart, lung, and ileum in both immediate or delayed resuscitation groups. Furthermore, ulinastatin infusion significantly reduced plasma and tissue concentrations of TBARS in both immediate or delayed resuscitation groups. Conclusions. These results indicate that ulinastatin can reduce fluid requirements through inhibition of lipid peroxidation.

Relationship between extravascular lung water and severity categories of acute respiratory distress syndrome by the Berlin definition.

IntroductionThe Berlin definition divides acute respiratory distress syndrome (ARDS) into three severity categories. The relationship between these categories and pulmonary microvascular permeability as well as extravascular lung water content, which is the hallmark of lung pathophysiology, remains to be elucidated. The aim of this study was to evaluate the relationship between extravascular lung water, pulmonary vascular permeability, and the severity categories as defined by the Berlin definition, and to confirm the associated predictive validity for severity.MethodsThe extravascular lung water index (EVLWi) and pulmonary vascular permeability index (PVPI) were measured using a transpulmonary thermodilution method for three consecutive days in 195 patients with an EVLWi of ≥10 mL/kg and who fulfilled the Berlin definition of ARDS. Collectively, these patients were seen at 23 ICUs. Using the Berlin definition, patients were classified into three categories: mild, moderate, and severe.ResultsCompared to patients with mild ARDS, patients with moderate and severe ARDS had higher acute physiology and chronic health evaluation II and sequential organ failure assessment scores on the day of enrollment. Patients with severe ARDS had higher EVLWi (mild, 16.1; moderate, 17.2; severe, 19.1; P <0.05) and PVPI (2.7; 3.0; 3.2; P <0.05). When categories were defined by the minimum PaO2/FIO2 ratio observed during the study period, the 28-day mortality rate increased with severity categories: moderate, odds ratio: 3.125 relative to mild; and severe, odds ratio: 4.167 relative to mild. On independent evaluation of 495 measurements from 195 patients over three days, negative and moderate correlations were observed between EVLWi and the PaO2/FIO2 ratio (r = -0.355, P<0.001) as well as between PVPI and the PaO2/FIO2 ratio (r = -0.345, P <0.001). ARDS severity was associated with an increase in EVLWi with the categories (mild, 14.7; moderate, 16.2; severe, 20.0; P <0.001) in all data sets. The value of PVPI followed the same pattern (2.6; 2.7; 3.5; P <0.001).ConclusionsSeverity categories of ARDS described by the Berlin definition have good predictive validity and may be associated with increased extravascular lung water and pulmonary vascular permeability.Trial registrationUMIN-CTR ID UMIN000003627

Rhodiola crenulataExtract Alleviates Hypoxic Pulmonary Edema in Rats

Sudden exposure of nonacclimatized individuals to high altitude can easily lead to high altitude illnesses. High altitude pulmonary edema (HAPE) is the most lethal form of high altitude illness. The present study was designed to investigate the ability of Rhodiola crenulata extract (RCE), an herbal medicine traditionally used as an antiacute mountain sickness remedy, to attenuate hypoxia-induced pulmonary injury. Exposure of animals to hypobaric hypoxia led to a significant increase in pathological indicators for pulmonary edema, including the lung water content, disruption of the alveolar-capillary barrier, and protein-rich fluid in the lungs. In addition, hypobaric hypoxia also increased oxidative stress markers, including (ROS) production, (MDA) level, and (MPO) activity. Furthermore, overexpression of plasma (ET-1), (VEGF) in (BALF), and (HIF-1α) in lung tissue was also found. However, pretreatment with RCE relieved the HAPE findings by curtailing all of the hypoxia-induced lung injury parameters. These findings suggest that RCE confers effective protection for maintaining the integrity of the alveolar-capillary barrier by alleviating the elevated ET-1 and VEGF levels; it does so by reducing hypoxia-induced oxidative stress. Our results offer substantial evidence to support arguments in favor of traditional applications of Rhodiola crenulata for antihigh altitude illness.

The effects of ulinastatin on systemic inflammation, visceral vasopermeability and tissue water content in rats with scald injury

The aim of this study was to examine whether administration of ulinastatin inhibits pro-inflammatory mediators and ameliorate visceral vasopermeability both in a rat model of major burn, and also in rat cultured endothelial cells stimulated with permeability-evoking mediators. Plasma levels of tumor necrosis factor-alpha (TNF-α), C-reactive protein (CRP), myeloperoxidase (MPO), microvascular permeability, and water content of organ tissues were evaluated in a rodent model of a 55% TBSA full-thickness scald injury. Microvascular permeability was also evaluated with a cultured pulmonary microvascular endothelial cells (PMECs) monolayer after stimulation with trypsin, bradykinin, histamine, prostaglandin E2 and burn serum. We found that the plasma levels of TNF-α, CRP, MPO, vascular permeability and water content of heart, lung, kidney, and small intestine tissues were significantly increased in animals after scald injury, and administration of ulinastatin lowered the levels TNF-α, CRP, MPO, vascular permeability and water content of those organ tissues. In vitro, ulinastatin lowered the levels of TNF-α, interleukin-6 (IL-6) and attenuated permeability in PMEC monolayers after being stimulated with burn serum or trypsin, but not by bradykinin, histamine or prostaglandin E2. These results indicate that ulinastatin attenuates the systemic inflammatory response and visceral vasopermeability both in vivo and vitro, and may serve as a therapeutic agent for prevention of systemic inflammatory response and leakage of fluid into tissue after major burn.

Lung injury following lower extremity blast trauma in rats

Lower extremity blast trauma is a common injury during armed conflict and after terrorist attacks with a high mortality, which is likely associated with distant vital organ injury. The current study aimed to investigate the underlying mechanisms of remote lung injury after blast lower extremity trauma. Sprague-Dawley rats were randomly divided into two groups: sham and blast. The blast group underwent blast trauma to the left hind limb using chartaceous electricity detonators, which was then subdivided into the time at which they were sacrificed: 0.5, 1, 3, and 6 hours. The sham group was also subdivided into the baseline control and time course groups. The baseline group was sacrificed 0.5 hours after artery cannulation and the time course at 6 hours after sham blast. The lungs were harvested for histologic analysis and water content measurement. Blood samples were harvested at each end of experiment and analyzed for cytokines, myeloperoxidase, malondialdehyde, and superoxide dismutase and cystathionine γ-lyase activity and hydrogen sulfide. Blast hind limb trauma induced alveolar injury and cell infiltration, together with an increase in lung water content, in a time-dependent manner. Plasma and lung levels of proinflammatory cytokines, tumor necrosis factor-α and interleukin 6, and malondialdehyde, were found to be significantly increased in conjunction with a rise in myeloperoxidase and a concurrent fall in superoxide dismutase, cystathionine γ-lyase, and hydrogen sulfide. Our data demonstrated that blast limb trauma causes remote lung injury, which is likely associated with remarkable inflammatory response, oxidative stress, and depletion of protective mechanisms.

Gadolinium Chloride Attenuates Sepsis-Induced Pulmonary Apoptosis and Acute Lung Injury

Gadolinium chloride (GdCl3), a Kupffer cells inhibitor, attenuates acute lung injury; however, the mechanisms behind this effect are not completely elucidated. We tested the hypothesis that GdCl3 acts through the inhibition of lung parenchymal cellular apoptosis. Two groups of rats were injected intraperitoneally with saline or E. coli lipopolysaccharide. In two additional groups, rats were injected with GdCl3 24 hrs prior to saline or LPS administration. At 12 hrs, lung injury, inflammation, and apoptosis were studied. Lung water content, myeloperoxidase activity, pulmonary apoptosis and mRNA levels of interleukin-1β, -2, -5, -6, -10 and TNF-α rose significantly in LPS-injected animals. Pretreatment with GdCl3 significantly reduced LPS-induced elevation of pulmonary water content, myeloperoxidase activity, cleaved caspase-3 intensity, and attenuated pulmonary TUNEL-positive cells. GdCl3 pre-treatment upregulated IL-1β, -2 and -10 pulmonary gene expression without significantly affecting the others. These results suggest that GdCl3 attenuates acute lung injury through its effects on pulmonary parenchymal apoptosis.

Effect of c-AMP-protein kinase A on up-regulation of heme oxygenase-1 expresion during lipopolysac-charide-induced acute lung injury in rats

Objective To evaluate the role of c-AMP-protein kinase A (cAMP-PKA) on the up-regulation of heme oxygenase-1 (HO-1) expression during lipopolysaccharide (LPS)-induced acute lung injury (ALI) in rats.Methods Forty-eight healthy male Sprague-Dawley rats,weighing 180-220 g,aged 2.5-3.0 months,were randomly divided into 4 groups (n =12 each)∶ normal control group (group C),ALI group (group ALI),H89 +ALI group (group H + ALI) and H89 group (group H).In group C,normal saline (solvent for LPS) 0.5 ml was injected via the femoral vein and normal saline (solvent for H89) 0.5 ml was injected subcutaneously 2 h later.In group ALI,10 mg/kg LPS 0.5 ml was injected via the femoral vein and normal saline 0.5 ml was injected subcutaneously 2 h later.In group H +ALI,10 mg/kg LPS 0.5 ml was injected via the femoral vein and 5 mg/kg H89 0.5ml was injected subcutaneously 2 h later.In group H,normal saline 0.5 ml was injected via the femoral vein and 5 mg/kg H89 0.5 ml was injected subcutaneously 2 h later.The rats were then sacrificed at 6 h after iv injection of LPS and the lungs were removed for microscopic examination and lung water content.The pathological changes of the lung were scored.The expression of HO-1 and PKA (by Western blot) and HO-1 mRNA (by RT-PCR) was detected.Results Compared with group C,the pathological score and lung water content were significantly increased,and the expression of HO-1,PKA and HO-1 mRNA was up-regulated in groups ALI and H +ALI (P ＜0.05),and no significant change was found in the parameters mentioned above in group H (P ＞ 0.05).The pathological score and lung water content were significantly higher,and the expression of HO-1,AP-1 and HO-1 mRNA was significantly lower in group H + ALI than in group ALI (P ＜ 0.05).Conclusion Activation of signaling pathway c-AMP-PKA is involved in the up-regulation of HO-1 expression during LPS-induced ALI in rats. Key words: Cyclic AMP-dependent protein kinases ; Heme oxygenase-1 ; Endotoxemia ; Respiratory distress syndrome, adult

Surfactant deactivation in a pediatric model induces hypovolemia and fluid shift to the extravascular lung compartment

Surfactant deficiency is the pivotal abnormality in Neonatal and Acute Respiratory Distress Syndrome. Surfactant deactivation can produce hypoxemia, loss of lung compliance, and pulmonary edema, but its circulatory consequences are less understood. To describe the sequential hemodynamic changes and pulmonary edema formation after surfactant deactivation in piglets. Surfactant deactivation was induced by tracheal instillation of polysorbate 20 in 15 anesthetized and mechanically ventilated Large White piglets. The hemodynamic consequences of surfactant deactivation were assessed at 30, 120, and 240min by transpulmonary thermodilution and traditional methods. Surfactant deactivation caused hypoxemia, reduced lung compliance, and progressively increased lung water content (P<0.01). Early hypovolemia was observed, with reductions of the global end-diastolic volume and stroke volume (P<0.05). Reduced cardiac output was observed at the end of the study (P<0.05). Standard monitoring was unable to detect these early preload alterations. Surprisingly, the bronchoalveolar protein content was greatly increased at the end of the study compared with baseline levels (P<0.01). This finding was inconsistent with the notion that the pulmonary edema induced by surfactant deactivation was exclusively caused by high surface tension. Hypovolemia develops early after surfactant deactivation, in part due to the resulting fluid shift from the intravascular compartment to the lungs.

Effect of safflor yellow injection on inhibiting lipopolysaccharide-induced pulmonary inflammatory injury in mice

To observe the effect of Safflor Yellow (SY) Injection on acute lung injury (ALI) induced by lipopolysaccharide (LPS) in mice. Seventy-two mice were divided into six groups: control (saline + saline); LPS (LPS + saline); SY Injection [LPS + SY (10, 20 or 40 mg/kg, intravenously)] and anisodamine (AD) (LPS + AD). Thirty minutes after SY or AD administration, 15 mg/kg LPS was given intraperitoneally. All animals were sacrificed 4 h after LPS injection. Arterial blood gas and lung water content index (LWCI) were measured. Lung tissue myeloperoxidase (MPO) activity was assayed. mRNA expression of inflammatory cytokines was assayed by reverse-transcription polymerase chain reaction. Lung morphological and nuclear factor (NF)-κB p65-positive cell changes were observed by HE and immunohistochemical staining. p38 mitogen-activated protein kinase (MAPK) phosphorylation was observed by Western blotting. After LPS administration, all animals displayed increased arterial carbon dioxide partial pressure (PaCO2) and decreased arterial oxygen partial pressure (PaO2), arterial oxygen saturation (SO2), HCO3 (-) concentration and pH, and increased LWCI, MPO activity, interleukin (IL)-1β, IL-6 and tumor necrosis factor (TNF)-α mRNA expression, NF-κB p65-positive staining and p38 MAPK activation compared with normal controls (all P<0.01). SY Injection significantly mitigated the LPS-induced increase in arterial PaCO and the decreases in arterial PaO2, SO2 and pH, and attenuated increases in LWCI and lung tissue MPO activity (all P<0.01). Moreover, SY Injection inhibited the increases in NF-κB p65 staining and in TNF-α, IL-1β and IL-6 mRNA expression (all P<0.01), and promoted the expression of the antiinflammatory cytokine IL-10 (P<0.05) following LPS injection. LPS-induced pulmonary p38 MAPK phosphorylation was suppressed by pretreatment with SY Injection (P<0.01). SY Injection ameliorates inflammatory ALI induced by LPS in mice.

Role of p38MAPK signaling pathway in up-regulation of heme oxygenase-1 expression in lung tissues in rats with acute lung injury induced by endotoxic shock

Objective To evaluate the role of p38MAPK signaling pathway in the up-regulation of heme oxygenase-1 (HO-1) expression in the lung tissue in rats with acute lung injury (AL1) induced by endotoxic shock.Methods Forty-eight male SD rats,aged 8 weeks,weighing 180-200 g,were randomly divided into 4 groups ( n =12 each):control group ( group C ) ; endotoxic shock group ( group LS );endotoxic shock +SB203580 (a specific p38MAPK inhibitor) group (group LSS) and SB203580 group (group SB).Normal saline 0.5ml was injected via the femoral vein in groups C and SB,while LPS 10 mg/kg (in 0.5 ml normal saline) was injected via the femoral vein in groups LS and LSS.When MAP was decreased to 75％ of baseline value,10％ dimethyl sulfoxide (DMSO) 0.1 ml was infused via the femoral vein in groups C and LS,while SB203580 5 mol/kg (in 10％ DMSO 0.1 ml) was infused via the femoral vein at a rate of 0.01 ml/min in groups LSS and SB.Arterial blood samples were obtained at 6 h after LPS or normal saline was given for blood gas analysis and oxygenation index (PaO2/FiO2) was calculated.Then the rats were sacrificed and the lungs were removed for microscopic examination.The pathological changes of the lung were scored.The lung water content was calculated.The MDA content,SOD activity,and expression of HO-1 mRNA and protein,p38MAPK protein and phospharylated p38MAPK (p-p38MAPK) protein were determined.Results Compared with group C,the oxygenation index and SOD activity were significantly decreased,the pathological score,lung water content and MDA content were significantly increased,and the expression of HO-1 mRNA and protein and p-p38MAPK protein was significantly up-regulated ( P＜0.05),while no significant change was found in p38MAPK protein expression in groups LS and LSS,and no significant change was found in the indexes mentioned above in group SB (P＞0.05).Compared with group LS,the oxygenation index and SOD activity were significantly increased,the pathological score,lung water content and MDA content were significantly decreased,the expression of HO-1 mRNA and protein was significantly up-regulated,and p-p38MAPK protein expression was down-regulated ( P＜0.05),and no significant change was found in p38MAPK protein expression in group LSS ( P＞0.05).Conclusion The inhibition of p38MAPK signaling pathway can lead to the up-regulation of HO-1 expression in lung tissues in rats with ALI induced by endotoxic shock. Key words: p38 Mitogen-activated protein kinases; Hemne oxygenase-1; Lung; Shock,septic; Respiratory distress syndrome,adult

Postinfection A77-1726 Treatment Improves Cardiopulmonary Function in H1N1 Influenza-Infected Mice

Acute respiratory disease is associated with significant morbidity and mortality in influenza. Because antiviral drugs are only effective early in infection, new agents are needed to treat nonvaccinated patients presenting with late-stage disease, particularly those who develop acute respiratory distress syndrome. We found previously that the de novo pyrimidine synthesis inhibitor A77-1726 reversed the influenza-induced impairment of alveolar fluid clearance. Patients with acute respiratory distress syndrome and intact alveolar fluid clearance demonstrate lower mortality than those with compromised fluid clearance. We therefore investigated the effects of treatment with nebulized A77-1726 (67.5 mg/kg) on indices of cardiopulmonary function relevant to the diagnosis of acute respiratory distress syndrome. BALB/cAnNCr mice (8-12 wk old) were inoculated intranasally with 10,000 plaque-forming units/mouse influenza A/WSN/33 (H1N1). Pulse oximetry was performed daily. Alveolar fluid clearance, lung water, and lung mechanics were measured at 2 and 6 days after inoculation in live, ventilated mice by BSA instillation, magnetic resonance imaging, and forced-oscillation techniques, respectively. A77-1726 treatment at 1 day after inoculation delayed mortality. Treatment on Days 1 or 5 reduced viral replication on Day 6, and improved alveolar fluid clearance, peripheral oxygenation, and cardiac function. Nebulized A77-1726 also reversed influenza-induced increases in lung water content and volume, improved pulmonary mechanics, reduced bronchoalveolar lavage fluid ATP and neutrophil content, and increased IL-6 concentrations. The ability of A77-1726 to improve cardiopulmonary function in influenza-infected mice and to reduce the severity of ongoing acute respiratory distress syndrome late in infection suggests that pyrimidine synthesis inhibitors are promising therapeutic candidates for the management of severe influenza.

Evaluation of the antifibrotic effect of fenofibrate and rosiglitazone on bleomycin-induced pulmonary fibrosis in rats

Idiopathic pulmonary fibrosis is the most prevalent chronic fibrosing lung disease. Peroxisome proliferator-activated receptors-gamma agonists provide potential therapy for fibrotic diseases of the lung. Peroxisome proliferator-activated receptors-alpha agonists may be helpful in the treatment of lung inflammatory diseases, however their therapeutic potential on the “fibro-proliferative” process and extracellular matrix accumulation in idiopathic pulmonary fibrosis has been less well studied. So, the present study was conducted to evaluate the anti-fibrotic effects of fenofibrate (peroxisome proliferator-activated receptors-alpha agonist) alone and in combination with rosiglitazone (peroxisome proliferator-activated receptors-gamma agonist) on lung injury induced by bleomycin administration. Oral administration of either rosiglitazone (5mg/kg/d) or fenofibrate (100mg/kg/d) for 14 days, attenuated the severity of bleomycin-induced lung injury and fibrosis through decreasing lung water contents, lung fibrotic grading, lung hydroxyproline contents and lung transforming growth factor-beta1 levels; with no significant difference between them. Combined low doses of rosiglitazone (1mg/kg/d) and fenofibrate (30mg/kg/d) provided more benefits than full separate doses of each on the deleterious effects accompanied bleomycin administration.These findings suggested the potential use of peroxisome proliferator-activated receptors-alpha ligands as anti-fibrotic agents in lung fibrosis. Additionally, the concurrent administration of fenofibrate and rosiglitazone in low doses has synergistic effect and enhanced the beneficial effects afforded by either fenofibrate or rosiglitazone.

Pulmonary microvascular hyperpermeability and expression of vascular endothelial growth factor in smoke inhalation- and pneumonia-induced acute lung injury

IntroductionAcute lung injury (ALI) and sepsis are major contributors to the morbidity and mortality of critically ill patients. The current study was designed further evaluate the mechanism of pulmonary vascular hyperpermeability in sheep with these injuries. MethodsSheep were randomized to a sham-injured control group (n=6) or ALI/sepsis group (n=7). The sheep in the ALI/sepsis group received inhalation injury followed by instillation of Pseudomonas aeruginosa into the lungs. These groups were monitored for 24h. Additional sheep (n=16) received the injury and lung tissue was harvested at different time points to measure lung wet/dry weight ratio, vascular endothelial growth factor (VEGF) mRNA and protein expression as well as 3-nitrotyrosine protein expression in lung homogenates. ResultsThe injury induced severe deterioration in pulmonary gas exchange, increases in lung lymph flow and protein content, and lung water content (P<0.01 each). These alterations were associated with elevated lung and plasma nitrite/nitrate concentrations, increased tracheal blood flow, and enhanced VEGF mRNA and protein expression in lung tissue as well as enhanced 3-nitrotyrosine protein expression (P<0.05 each). ConclusionsThis study describes the time course of pulmonary microvascular hyperpermeability in a clinical relevant large animal model and may improve the experimental design of future studies.