Ouabain, a Na(+)/K(+)-ATPase inhibitor, induces slowly adapting pulmonary stretch receptors (SARs) to discharge paradoxically. Paradoxical discharge is characterized by increased SAR activity during lung deflation coupled with silence during lung inflation. We hypothesized that over-excitation silences the SARs. Accordingly, if cyclic inflation pressure was reduced so as to lower SAR stimulation, paradoxical discharge would be prevented. In the present study, single-unit activity of SARs was recorded in anesthetized, open-chest and mechanically ventilated rabbits with positive-end-expiratory pressure (PEEP). After microinjection of ouabain into the receptive field, SAR activity initially increased and then gradually became paradoxical. During paradoxical cycling, SAR activity started and stopped abruptly, oscillating between high frequency discharge during lung deflation and silence during peak inflation. Removing PEEP reduced basal cyclic stimulation and returned the discharge pattern to normal, that is, SAR activity was highest at peak inflation pressure but silent during deflation. It is speculated that stretching SARs causes Na(+) influx, producing generator potential (GP). Normally, GP recovers by Na(+) extrusion via Na(+)/K(+)-ATPase. Ouabain inhibits the ATPase, which limits Na(+) extrusion, and thus sustains the GP. Therefore, after ouabain microinjection, lung inflation will further increase GP, causing over-excitation to silence the SARs.
Action Potentials ; physiology ; Adaptation, Physiological ; drug effects ; Animals ; Lung ; drug effects ; physiology ; Male ; Mechanoreceptors ; physiology ; Ouabain ; pharmacology ; Pulmonary Stretch Receptors ; drug effects ; physiology ; Pulmonary Ventilation ; drug effects ; physiology ; Rabbits ; Sodium-Potassium-Exchanging ATPase ; antagonists & inhibitors ; physiology ; Vagus Nerve ; physiology

OBJECTIVETo assess the effect of tetrandrine (Tet) pulmonary targeting microspheres on hypoxic pulmonary hypertension and evaluate its selective action on pulmonary circulation.

METHODSTwenty rats were exposed to hypoxic conditions for 3 weeks. Ten rats were used as normoxic controls. We administered Tet pulmonary targeting microspheres to 10 hypoxic rats and Tet aqueous solution to 10 hypoxic rats and the 10 control rats. Mean pulmonary arterial pressure (mPAP) was measured by a right cardiac catheterization, and mean systemic blood pressure (mSBP) was measured by left femoral catheterization.

RESULTSRats exposed to hypoxia developed pulmonary hypertension. The decrease in mPAP in rats treated with Tet pulmonary targeting microspheres was significantly greater than that in rats receiving Tet aqueous solution (P < 0.05), and the effects were longer with Tet pulmonary targeting microspheres. Moreover, Tet pulmonary targeting microspheres, unlike Tet aqueous solution, did not decrease mSBP.

CONCLUSIONTet pulmonary targeting microspheres were more effective than Tet aqueous solution treating hypoxic pulmonary hypertension and acted selectively on the pulmonary circulation.

Alkaloids ; administration & dosage ; Animals ; Benzylisoquinolines ; Blood Pressure ; drug effects ; Hypertension, Pulmonary ; drug therapy ; Hypoxia ; physiopathology ; Lung ; drug effects ; Male ; Microspheres ; Pulmonary Artery ; drug effects ; physiology ; Rats ; Rats, Wistar

BACKGROUNDThe University of Wisconsin colloid based preserving solution (UW solution) is the most efficient preserving solution for multiorgan transplantation. Unfortunately, unavailability of delayed organ preserving solutions hindered further progression of cardinal organ transplantation in China. In this study, we validated an organ preserving Changzheng Organ Preserving Solution (CZ-1 solution) and compared it with UW solution.

METHODSA series of studies were conducted on how and how long CZ-1 solution could preserve the kidneys, livers, hearts, lungs and pancreas of New Zealand rabbits and SD rats. Morphology of transplanted organs was studied by visible microscopy and electron microscopy; biochemical and physiological functions and the survival rate of the organs during prolonged cold storage were studied.

RESULTSThere was no significant difference between CZ-1 and UW solutions in preserving the kidneys, livers, hearts or lungs of rabbits; kidneys, livers, intestinal mucosa or pancreases of SD rats or five deceased donors' testicles. In some aspects, such as preserving rabbits' hearts, rats' intestinal mucosa and pancreases, the effect of CZ-1 solution was superior to UW solution. CZ-1 could safely preserve kidneys for 72 hours, livers for 24 hours, hearts for 18 hours and lungs for 8 hours for SD rats. Twelve kidneys preserved in cold CZ-1 solution for 22 - 31 hours were transplanted successfully and the mean renal function recovery time was (3.83 +/- 1.68) days.

CONCLUSIONSCZ-1 solution is as effective as UW solution for organ preservation. The development of CZ-1 solution not only reduces costs and improves preservation of organs, but also promotes future development of organ transplantation in China.

Adenosine ; pharmacology ; Allopurinol ; pharmacology ; Animals ; China ; Glutathione ; pharmacology ; Heart ; drug effects ; physiology ; Heart Transplantation ; methods ; Insulin ; pharmacology ; Intestine, Small ; drug effects ; physiology ; Kidney ; drug effects ; physiology ; Kidney Transplantation ; methods ; Liver ; drug effects ; physiology ; Liver Transplantation ; methods ; Lung ; drug effects ; physiology ; Lung Transplantation ; methods ; Male ; Organ Preservation ; economics ; methods ; Organ Preservation Solutions ; pharmacology ; Pancreas ; drug effects ; physiology ; Pancreas Transplantation ; methods ; Pharmaceutical Solutions ; pharmacology ; Rabbits ; Raffinose ; pharmacology ; Testis ; drug effects ; physiology

Mycobacterium abscessus (M. abscessus) is the second most common nontuberculous mycobacteria (NTM) in South Korea. Nevertheless, the diagnosis and treatment of M. abscessus lung disease can be problematic. Surgical resection has been tried for patients with localized M. abscessus lung disease refractory to medical treatment. Here, we report on a 25-year-old woman with M. abscessus lung disease who had been diagnosed and treated three times for pulmonary tuberculosis. She was initially diagnosed as having M. intracellulare lung disease; however, M. abscessus was isolated after several months of medication. She had multiple bronchiectatic and cavitary lesions bilaterally, and M. abscessus was repeatedly isolated from her sputa despite prolonged treatment with clarithromycin, ethambutol, moxifloxacin, and amikacin. She improved only after sequential bilateral lung resection. Based on the experience with this patient, we suggest that, if medical treatment fails, surgical resection of a diseased lung should be considered even in patients with bilateral lesions.
Adult ; Anti-Bacterial Agents/pharmacology/*therapeutic use ; Female ; Humans ; Lung Diseases/*drug therapy/*microbiology/surgery ; Mycobacteria, Atypical/drug effects/*physiology

Cell Proliferation ; drug effects ; Cells, Cultured ; Dose-Response Relationship, Drug ; Humans ; Lung ; cytology ; drug effects ; Vascular Endothelial Growth Factor A ; pharmacology ; Vascular Endothelial Growth Factor Receptor-2 ; physiology

BACKGROUNDThrombin is a multifunctional serine protease that plays a crucial role in hemostasis following tissue injury. In addition to its procoagulation effect, thrombin is also a potent mesenchymal cell mitogen, therefore it plays important roles in the local proliferation of mesenchymal cells in the tissue repair process. Reactive oxygen species (ROS) can induce some human cells to proliferate at lower rates while at higher concentrations they promote cells to undergo apoptosis or necrosis. Accumulative evidence suggests that thrombin can induce some cells to produce ROS. Based on these observations, we provide a hypothesis that thrombin can stimulate human lung fibroblasts to produce ROS, which play an important role in human lung fibroblast proliferation.

METHODSROS were detected in fibroblasts at 30 minutes and 60 minutes following thrombin (20 U/ml) exposure using flow cytometry. The ratio of reduced glutathione/oxidized glutathione (GSH/GSSG) was assayed in lung fibroblasts using a commercial kit following treatment with thrombin at different concentrations. NADPH oxidase and the extracellular regulated kinase1/2 (ERK1/2) signaling pathway were detected by Western blotting after thrombin stimulation to lung fibroblasts.

RESULTSThrombin, at 20 U/ml, stimulated human lung fibroblasts (HLF) to generate ROS in a time dependent manner. The ratio of GSH/GSSG in fibroblasts treated with thrombin showed a significant decrease. NADPH oxidase was activated and the ERK1/2 signal pathway was involved in the proliferation process of fibroblasts treated with thrombin.

CONCLUSIONThe activation of NADPH oxidase by thrombin leads to the production of ROS, which promotes fibroblasts proliferation via activation of the ERK1/2 signaling pathway.

Cell Proliferation ; drug effects ; Cells, Cultured ; Extracellular Signal-Regulated MAP Kinases ; analysis ; physiology ; Fibroblasts ; drug effects ; physiology ; Flow Cytometry ; Glutathione ; metabolism ; Humans ; Lung ; cytology ; NADPH Oxidases ; analysis ; physiology ; Reactive Oxygen Species ; metabolism ; Signal Transduction ; physiology ; Thrombin ; pharmacology

OBJECTIVETo investigate the role of calcineurin (CaN) in the lung fibroblast proliferation and collagen synthesis induced by basic fibroblast growth factor (bFGF).

METHODSWe used Western blot and immunohistochemical methods for investigating the content and distribution of calcineurin in the lung tissue. Calcineurin activity in different tissues was measured using (32)P-labelled substrate. In the primary culture of lung fibroblasts, (3)H-thymidine ((3)H-TdR) and (3)H-proline incorporation methods were used to study the effect of cyclosporin A (CsA), an inhibitor of calcineurin, on the lung fibroblast DNA and collagen synthesis stimulated by bFGF.

RESULTSWe found that calcineurin was expressed in lung tissue and has phosphatase activity (7.1 +/- 2.0 pmol Pi/mg pr/min). CsA (10(-8) - 10(-6) mol/L) inhibited lung fibroblast (3)H-TdR incorporation induced by bFGF in a dose-dependent manner, with the inhibitory rates by 20%, 46% and 66% (P < 0.01). CsA (10(-7) - 10(-6) mol/L) inhibited (3)H-proline incorporation in lung fibroblasts stimulated by bFGF, with the inhibitory rates by 21% and 37% (P < 0.01). In a culture medium, CsA (10(-8) - 10(-6) mol/L) inhibited (3)H-proline secretion induced by bFGF in a dose-dependent manner, with the inhibitory rates by 19%, 29% (P < 0.05) and 56% (P < 0.01). CsA (10(-7) mol/L) could inhibit calcineurin activity by 44% in lung fibroblasts (P < 0.01).

CONCLUSIONSCalcineurin is expressed in lung tissue and has phosphatase activity. It is involved in the bFGF stimulated lung fibroblast DNA and collagen synthesis.

Animals ; Calcineurin ; analysis ; physiology ; Cell Division ; Cell Survival ; drug effects ; Collagen ; biosynthesis ; Fibroblast Growth Factor 2 ; pharmacology ; Fibroblasts ; drug effects ; physiology ; Lung ; cytology ; drug effects ; metabolism ; Rats ; Rats, Sprague-Dawley

BACKGROUND/AIMS: Peroxiredoxin (Prx) belongs to a ubiquitous family of antioxidant enzymes that regulates many cellular processes through intracellular oxidative signal transduction pathways. Silica-induced lung damage involves reactive oxygen species (ROS) that trigger subsequent toxic effects and inflammatory responses in alveolar epithelial cells resulting in fibrosis. Therefore, we investigated the role of Prx in the development of lung oxidant injury caused by silicosis, and determined the implication of ROS in that process. METHODS: Lung epithelial cell lines A549 and WI26 were treated with 1% silica for 0, 24, or 48 hours, following pretreatment of the A549 cells with N-acetyl-L-cysteine and diphenylene iodonium and no pretreatment of the WI26 cells. We transfected an HA-ubiquitin construct into the A549 cell line and then analyzed the cells via Western blotting and co-immunoprecipitation. RESULTS: Silica treatment induced cell death in the A549 lung epithelial cell line and selectively degraded Prx I without impairing protein synthesis in the A549 cells, even when the ROS effect was blocked chemically by N-acetyl-L-cysteine. A co-immunoprecipitation study revealed that Prx I did not undergo ubiquitination. CONCLUSIONS: Silica treatment induces a decrease of Prx I expression in lung epithelial cell lines regardless of the presence of ROS. The silica-induced degradation of Prx does not involve the ubiquitin-proteasomal pathway.
Cell Line ; Epithelial Cells/drug effects/metabolism ; Humans ; Lung/chemistry/*drug effects/metabolism ; Peroxiredoxins/analysis/*physiology ; Protein Isoforms ; Reactive Oxygen Species/metabolism ; Silicon Dioxide/*toxicity ; Ubiquitin/metabolism

BACKGROUNDWith the widespread use of ventilators in treating critically ill patients, the morbidity of ventilator-induced lung injury (VILI) is increasing accordingly. VILI is characterized by a considerable increase in microvascular leakiness and activation of inflammatory processes. In this study we investigated the effects of inflammatory mediators in VILI rat serum on endothelial cytoskeleton and monolayer cellular permeability, as well as the therapeutic effect of ulinastatin, to explore the pathogenesis and the relationship between biotrauma and lung oedema induced by VILI.

METHODSThirty healthy male Sprague-Dawley rats were randomly divided into three groups: group A (normal tidal volume ventilation), group B (high tidal volume ventilation) and group C (high tidal volume ventilation plus ulinastatin). The serum of each rat after ventilation was added to endothelial cell line ECV-304 medium for two hours to observe the effects of serum and/or ulinastatin on endothelial fibrous actin and permeability.

RESULTSCompared to rats ventilated with normal tidal volume, serum of rats ventilated with high tidal volume caused a striking reorganization of actin cytoskeleton with a weakening of fluorescent intensity at the peripheral filament bands and formation of the long and thick stress fibres in the centre resulting in endothelial contraction and higher permeability. Prior treatment with ulinastatin lessened the above changes significantly. The changes of permeability coefficient of endothelial permeability after group A, B or C rats serum stimulation were (6.95 +/- 1.66)%, (27.50 +/- 7.77)% and (17.71 +/- 4.66)% respectively with statistically significant differences (P < 0.05) among the three groups.

CONCLUSIONSThe proinflammatory mediators in the serum of the rats given high tidal volume ventilation increases endothelial permeability by reorganizing actin cytoskeleton, and pretreatment with ulinastatin lessens the permeability by inhibiting of proinflammatory mediators.

Actins ; analysis ; metabolism ; Animals ; Anti-Inflammatory Agents ; therapeutic use ; Cell Membrane Permeability ; drug effects ; Cells, Cultured ; Endothelial Cells ; drug effects ; metabolism ; physiology ; Glycoproteins ; therapeutic use ; Humans ; Lung ; drug effects ; metabolism ; Lung Diseases ; etiology ; physiopathology ; prevention & control ; Lung Injury ; Male ; Microscopy, Fluorescence ; methods ; Random Allocation ; Rats ; Rats, Sprague-Dawley ; Respiration, Artificial ; adverse effects ; Tidal Volume ; drug effects ; Ventilators, Mechanical ; adverse effects

To investigate the effect of apigenin on self-renewal for sphere-forming cells in human small cell lung cancer cell line NCI-H446 and the underlying mechanisms.
 Methods: Sphere-forming cells from NCI-H446 cell line were cultured in stem cell-conditioned culture medium with ultra-low attachment surface plates. The rate of sphere-forming cells in the second passage sphere-forming cells was used to evaluate the inhibitory effects of apigenin on the self-renewal for sphere-forming cells. The protein level of urokinase-type plasminogen activator receptor (uPAR) in spheroids was analyzed by Western blot.
 Results: Apigenin signifcantly inhibited the self-renewal of the second passage sphere-forming cells [0, 5.0, 10.0, 20.0 μmol/L apigenin: (18.2±1.9)%, (13.6±1.7)%, (10.6±1.6)%, (6.9±1.3)%, respectively] and down-regulated uPAR expression in a concentration-dependent manner (P<0.05).
 Conclusion: Apigenin inhibits the self-renewal capacity of sphere-forming cells in NCI-H446 cells, which may be associated with down-regulation of uPAR expression.
Apigenin ; pharmacology ; Cell Line, Tumor ; Down-Regulation ; drug effects ; genetics ; Humans ; Lung Neoplasms ; Neoplastic Stem Cells ; drug effects ; pathology ; physiology ; Receptors, Cell Surface ; Receptors, Urokinase Plasminogen Activator ; drug effects ; genetics ; metabolism ; Signal Transduction ; Small Cell Lung Carcinoma ; drug therapy ; pathology ; Spheroids, Cellular ; drug effects ; physiology ; Stem Cells