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Burkhardt W, Kraft S, Ochs M, Proquitté H, Mense L, Rüdiger M. Persurf, a new method to improve surfactant delivery: a study in surfactant depleted rats. PLoS One 2012; 7:e47923. [PMID: 23082229 PMCID: PMC3474734 DOI: 10.1371/journal.pone.0047923] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2011] [Accepted: 09/19/2012] [Indexed: 11/18/2022] Open
Abstract
PURPOSE Exogenous surfactant is not very effective in adults with ARDS, since surfactant does not reach atelectatic alveoli. Perfluorocarbons (PFC) can recruit atelectatic areas but do not replace impaired endogenous surfactant. A surfactant-PFC-mixture could combine benefits of both therapies. The aim of the proof-of-principal-study was to produce a PFC-in-surfactant emulsion (Persurf) and to test in surfactant depleted Wistar rats whether Persurf achieves I.) a more homogenous pulmonary distribution and II.) a more homogenous recruitment of alveoli when compared with surfactant or PFC alone. METHODS Three different PFC were mixed with surfactant and phospholipid concentration in the emulsion was measured. After surfactant depletion, animals either received 30 ml/kg of PF5080, 100 mg/kg of stained (green dye) Curosurf™ or 30 ml/kg of Persurf. Lungs were fixated after 1 hour of ventilation and alveolar aeration and surfactant distribution was estimated by a stereological approach. RESULTS Persurf contained 3 mg/ml phospholipids and was stable for more than 48 hours. Persurf-administration improved oxygenation. Histological evaluation revealed a more homogenous surfactant distribution and alveolar inflation when compared with surfactant treated animals. CONCLUSIONS In surfactant depleted rats administration of PFC-in-surfactant emulsion leads to a more homogenous distribution and aeration of the lung than surfactant alone.
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Affiliation(s)
- Wolfram Burkhardt
- Department for Neonatology and Pediatric Intensive Care Medicine, Klinik für Kinderheilkunde, Universitätsklinikum Carl Gustav Carus, Medizinische Fakultät der Technischen Universität Dresden, Dresden, Germany
| | - Stephan Kraft
- Department for Pediatric Surgery, Klinikum Mutterhaus der Borromäerinnen, Trier, Germany
| | - Matthias Ochs
- Institute of Functional and Applied Anatomy, Hannover Medical School, Hannover, Germany
| | - Hans Proquitté
- Clinic for Neonatology, Charité, Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Lars Mense
- Department for Neonatology and Pediatric Intensive Care Medicine, Klinik für Kinderheilkunde, Universitätsklinikum Carl Gustav Carus, Medizinische Fakultät der Technischen Universität Dresden, Dresden, Germany
| | - Mario Rüdiger
- Department for Neonatology and Pediatric Intensive Care Medicine, Klinik für Kinderheilkunde, Universitätsklinikum Carl Gustav Carus, Medizinische Fakultät der Technischen Universität Dresden, Dresden, Germany
- * E-mail:
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Wemhöner A, Hackspiel I, Hobi N, Ravasio A, Haller T, Rüdiger M. Effects of perfluorocarbons on surfactant exocytosis and membrane properties in isolated alveolar type II cells. Respir Res 2010; 11:52. [PMID: 20459693 PMCID: PMC2876085 DOI: 10.1186/1465-9921-11-52] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/08/2009] [Accepted: 05/09/2010] [Indexed: 01/05/2023] Open
Abstract
Background Perfluorocarbons (PFC) are used to improve gas exchange in diseased lungs. PFC have been shown to affect various cell types. Thus, effects on alveolar type II (ATII) cells and surfactant metabolism can be expected, data, however, are controversial. Objective The study was performed to test two hypotheses: (I) the effects of PFC on surfactant exocytosis depend on their respective vapor pressures; (II) different pathways of surfactant exocytosis are affected differently by PFC. Methods Isolated ATII cells were exposed to two PFC with different vapor pressures and spontaneous surfactant exocytosis was measured. Furthermore, surfactant exocytosis was stimulated by either ATP, PMA or Ionomycin. The effects of PFC on cell morphology, cellular viability, endocytosis, membrane permeability and fluidity were determined. Results The spontaneous exocytosis was reduced by PFC, however, the ATP and PMA stimulated exocytosis was slightly increased by PFC with high vapor pressure. In contrast, Ionomycin-induced exocytosis was decreased by PFC with low vapor pressure. Cellular uptake of FM 1-43 - a marker of membrane integrity - was increased. However, membrane fluidity, endocytosis and viability were not affected by PFC incubation. Conclusions We conclude that PFC effects can be explained by modest, unspecific interactions with the plasma membrane rather than by specific interactions with intracellular targets.
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Affiliation(s)
- Andreas Wemhöner
- University Hospital Dresden, Department for Pediatric Intensive Care and Neonatology, Technical University Dresden, Germany
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Haufe D, Koenigshausen E, Knels L, Wendel M, Stehr SN, Koch T. Leukocyte antibacterial functions are not impaired by perfluorocarbon exposure in vitro. Am J Physiol Lung Cell Mol Physiol 2008; 295:L134-42. [DOI: 10.1152/ajplung.00338.2007] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Application of liquid, aerosolized, and vaporized perfluorocarbons (PFC) in acute lung injury has shown anti-inflammatory effects. Although this may be beneficial in states of pulmonary hyperinflammation, it also could increase susceptibility to nosocomial lung infection. We hypothesized that PFC impair cellular host defense and therefore investigated in an in vitro model the influence of perfluorohexane (PFH) on crucial mechanisms of bacterial elimination in human neutrophils and monocytes. Using scanning and transmission electron microscopy, we could show membrane-bound and ingested PFH particles that morphologically did not alter adherence and phagocytosis of Escherichia coli or leukocyte viability. The amount of adherent and phagocytosed bacteria as determined by flow cytometry was not influenced in cells only pretreated with PFH for 1 and 4 h. When PFH was present during E. coli challenge, bacterial adherence was decreased in polymorphonuclear neutrophils, but respective intracellular uptake was not impaired and was even significantly promoted in monocytes. Overall, E. coli-induced respiratory burst capacity was not reduced by PFH. Our findings provide evidence that key functions of innate host defense are not compromised by PFH treatment in vitro.
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Burkhardt W, Koehne P, Wissel H, Graf S, Proquitté H, Wauer RR, Rüdiger M. Intratracheal perfluorocarbons diminish LPS-induced increase in systemic TNF-alpha. Am J Physiol Lung Cell Mol Physiol 2008; 294:L1043-8. [PMID: 18359887 DOI: 10.1152/ajplung.00125.2007] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022] Open
Abstract
Perfluorocarbons (PFC) reduce the production of various inflammatory cytokines, including TNF-alpha. The anti-inflammatory effect is not entirely understood. If anti-inflammatory properties are caused by a mechanical barrier, PFC in the alveoli should have no effect on the inflammatory response to intravenous LPS administration. To test that hypothesis, rats (n=31) were administered LPS intravenously and were either spontaneously breathing (Spont), conventionally ventilated (CMV), or receiving partial liquid ventilation (PLV). Serum concentration of TNF-alpha was measured. The pulmonary expressions of TNF-alpha and TNF-alpha receptor 1 protein and of TNF-alpha and ICAM-1 mRNA were determined. LPS caused a significant (P<0.001) increase in serum TNF-alpha. Serum TNF-alpha concentration was similar in LPS/Spont (525+/-180 pg/ml) and LPS/CMV (504+/-154 pg/ml) but was significantly (P<0.001) lower in animals of the LPS/PLV group (274+/-101 pg/ml). Immunohistochemical data on TNF-alpha protein expression showed a LPS-induced increase in TNF-alpha and TNF-alpha receptor 1 expression that was diminished by partial liquid ventilation. PCR measurements revealed a lower expression of TNF-alpha and ICAM-1 mRNA in LPS/PLV than in LPS/CMV or LPS/Spont animals. Semiquantitative histological evaluation revealed only minor alveolar inflammation with no significant differences between the groups. Low serum TNF-alpha concentration in PFC-treated animals is most likely explained by a decreased production of TNF-alpha in the lung.
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Affiliation(s)
- Wolfram Burkhardt
- Dept. for Neonatology and Pediatric Intensive Care Medicine, Klinik für Kinderheilkunde, Universitätsklinikum Carl Gustav Carus, Medizinische Fakultät der Technischen Universität Dresden, Fetscherstr. 74, 01307 Dresden, Germany
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Rüdiger M, Wendt S, Köthe L, Burkhardt W, Wauer RR, Ochs M. Alterations of alveolar type II cells and intraalveolar surfactant after bronchoalveolar lavage and perfluorocarbon ventilation. An electron microscopical and stereological study in the rat lung. Respir Res 2007; 8:40. [PMID: 17550584 PMCID: PMC1892019 DOI: 10.1186/1465-9921-8-40] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2006] [Accepted: 06/05/2007] [Indexed: 11/20/2022] Open
Abstract
Background Repeated bronchoalveolar lavage (BAL) has been used in animals to induce surfactant depletion and to study therapeutical interventions of subsequent respiratory insufficiency. Intratracheal administration of surface active agents such as perfluorocarbons (PFC) can prevent the alveolar collapse in surfactant depleted lungs. However, it is not known how BAL or subsequent PFC administration affect the intracellular and intraalveolar surfactant pool. Methods Male wistar rats were surfactant depleted by BAL and treated for 1 hour by conventional mechanical ventilation (Lavaged-Gas, n = 5) or partial liquid ventilation with PF 5080 (Lavaged-PF5080, n = 5). For control, 10 healthy animals with gas (Healthy-Gas, n = 5) or PF5080 filled lungs (Healthy-PF5080, n = 5) were studied. A design-based stereological approach was used for quantification of lung parenchyma and the intracellular and intraalveolar surfactant pool at the light and electron microscopic level. Results Compared to Healthy-lungs, Lavaged-animals had more type II cells with lamellar bodies in the process of secretion and freshly secreted lamellar body-like surfactant forms in the alveoli. The fraction of alveolar epithelial surface area covered with surfactant and total intraalveolar surfactant content were significantly smaller in Lavaged-animals. Compared with Gas-filled lungs, both PF5080-groups had a significantly higher total lung volume, but no other differences. Conclusion After BAL-induced alveolar surfactant depletion the amount of intracellularly stored surfactant is about half as high as in healthy animals. In lavaged animals short time liquid ventilation with PF5080 did not alter intra- or extracellular surfactant content or subtype composition.
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Affiliation(s)
- Mario Rüdiger
- Clinic for Neonatology, Charité Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
- Clinic for Pediatrics, Pädiatrie IV – Neonatologie; Medical University of Innsbruck, Innsbruck, Austria
| | - Sebastian Wendt
- Department of Anatomy, Division of Electron Microscopy, Georg-August-University, Göttingen, Germany
| | - Lars Köthe
- Department of Anatomy, Division of Electron Microscopy, Georg-August-University, Göttingen, Germany
| | - Wolfram Burkhardt
- Clinic for Pediatrics, Pädiatrie IV – Neonatologie; Medical University of Innsbruck, Innsbruck, Austria
| | - Roland R Wauer
- Clinic for Neonatology, Charité Universitätsmedizin Berlin, Campus Mitte, Berlin, Germany
| | - Matthias Ochs
- Department of Anatomy, Division of Electron Microscopy, Georg-August-University, Göttingen, Germany
- Institute of Anatomy, Experimental Morphology, University of Bern, Bern, Switzerland
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Wissel H, Burkhardt W, Rupp J, Wauer RR, Rüdiger M. Perfluorocarbons decrease Chlamydophila pneumoniae-mediated inflammatory responses of rat type II pneumocytes in vitro. Pediatr Res 2006; 60:264-9. [PMID: 16857767 DOI: 10.1203/01.pdr.0000233033.82664.91] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Chlamydophila pneumoniae alter the expression of Toll-like receptor (TLR) 4 in alveolar type II (ATII)-cells. Subsequently nuclear factor kappaB (NF-kappaB) is activated and tumor necrosis factor-alpha (TNF-alpha) and macrophage inflammatory protein 2 (MIP-2) are produced. Perfluorocarbons (PFC) are beneficial in animals with bacterial pneumonia and reduce production of TNF-alpha. Using isolated ATII-cells, it was studied whether PFC prevent C. pneumoniae-induced TNF-alpha and MIP-2 release and what the underlying pathway is. PF5080 preincubation prevented C. pneumoniae-induced secretion of TNF-alpha (43 +/- 10 versus 661 +/- 41 pg/mL) and MIP-2 (573 +/- 41 versus 4786 +/- 502 pg/mL). The C. pneumoniae-induced 2.2-fold increase of TNF-alpha Receptor 1 expression was reduced by PF5080. C. pneumoniae reduced cytoplasmatic IkappaBalpha (3.7 +/- 0.3 versus 14 +/- 1) and increased NF-kappaB p65 (31 +/- 7.5 versus 3.6 +/- 1.1) compared with control. PF5080 prevented NF-kappaB activation. TLR4 expression was 1.5-fold higher after C. pneumoniae incubation, but remained at control levels after PF5080 pretreatment. After 24 h of C. pneumoniae incubation, in 88 +/- 6% of cells bacteria were found in the perinuclear region and in 50% of these cells bacteria adhered to cellular surface. After PF5080 preincubation, C. pneumoniae were in 32 +/- 4% attached to and in 5 +/- 1% internalized in ATII-cells. Since PF5080 was found in ATII-cell membranes, PF5080 effect could be explained by an alteration of the cellular membrane, preventing activation of the inflammatory cascade.
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Affiliation(s)
- Heide Wissel
- Clinic for Neonatology, Campus Charité Mitte, D-10098 Berlin, Germany
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Abstract
In this review of liquid ventilation, concepts and applications are presented that summarise the pulmonary applications of perfluorochemical liquids. Beginning with the question of whether this alternative form of respiratory support is needed and ending with lessons learned from clinical trials, the various methods of liquid assisted ventilation are compared and contrasted, evidence for mechanoprotective and cytoprotective attributes of intrapulmonary perfluorochemical liquid are presented and alternative intrapulmonary applications, including their use as vehicles for drugs, for thermal control and as imaging agents are presented.
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Affiliation(s)
- Marla R Wolfson
- Department of Physiology, Temple University School of Medicine, 3420 North Broad Street, Philadelphia, PA 19140, USA
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Burkhardt W, Proquitté H, Krause S, Wauer RR, Rüdiger M. Changes in FiO2 affect PaO2 with minor alterations in cerebral concentration of oxygenated hemoglobin during liquid ventilation in healthy piglets. Intensive Care Med 2004; 30:315-320. [PMID: 14722641 DOI: 10.1007/s00134-003-2090-7] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2003] [Accepted: 10/31/2003] [Indexed: 10/26/2022]
Abstract
OBJECTIVE To measure the impact of changes in the fraction of inspired oxygen (FiO2) on systemic and cerebral oxygen supply in gas and liquid ventilated healthy animals. DESIGN Interventional prospective animal study. SETTING University research laboratory. PARTICIPANTS Ten healthy, new-born piglets. INTERVENTIONS Variations in FiO2 during conventional mechanical ventilation (CMV) followed by partial liquid ventilation (PLV) with two different filling volumes of PF 5080 (10 vs. 30 ml/kg). MEASUREMENTS AND RESULTS Arterial blood gases were obtained 15 min after changing FiO2 and concentrations of cerebral oxygenated and total hemoglobin were determined with near infrared spectroscopy. During CMV an increase in FiO2 1.0 was associated with a constant rise in PaO2 but only a small increase in the cerebral concentration of oxygenated Hb. Initiation of PLV (at FiO2 of 1.0) caused a rapid drop in PaO2 towards values that were similar to CMV at FiO2 of 0.5. At FiO2 of 0.5 a reduction in oxygenated Hb was found in the 30 ml/kg filling group. Complete filling of the lungs with PFC caused a significant drop in total cerebral Hb concentration. CONCLUSIONS. According to our data, PLV in healthy lungs should be performed with a FiO2 of 1.0 and a small filling volume to avoid deterioration in cerebral oxygen supply.
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Affiliation(s)
- Wolfram Burkhardt
- Clinic of Neonatology, Charité-Mitte, Schumannstrasse 20, 10098, Berlin, Germany
| | - Hans Proquitté
- Clinic of Neonatology, Charité-Mitte, Schumannstrasse 20, 10098, Berlin, Germany
| | - Susann Krause
- Clinic of Neonatology, Charité-Mitte, Schumannstrasse 20, 10098, Berlin, Germany
| | - Roland R Wauer
- Clinic of Neonatology, Charité-Mitte, Schumannstrasse 20, 10098, Berlin, Germany
| | - Mario Rüdiger
- Clinic of Neonatology, Charité-Mitte, Schumannstrasse 20, 10098, Berlin, Germany.
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Rudiger M, Some M, Jarstrand C, Calkovska A, Linderholm B, Robertson B, Herting E. Influence of partial liquid ventilation on bacterial growth and alveolar expansion in newborn rabbits with group B-streptococcal pneumonia. Pediatr Res 2003; 54:808-13. [PMID: 12930916 DOI: 10.1203/01.pdr.0000088070.62177.3a] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Abstract
Partial liquid ventilation (PLV) with perfluorocarbons has been considered as an alternative therapy for severe inflammatory lung disease. The present study was performed to test whether PLV influences bacterial growth and lung histology in a rabbit model of congenital pneumonia caused by group B streptococci. Near-term newborn rabbits were tracheotomized, inoculated via the airways with group B streptococci, and subsequently ventilated for 5 h with either PLV or conventional ventilation. At 30 min after group B streptococci administration, animals in the PLV group (n = 16) received 30 mL/kg body weight of perfluorocarbon (PF 5080) via the tracheal tube. Evaporative losses were substituted with 20 mL/kg perfluorocarbon at hourly intervals. Identical volumes of air were injected in control animals at the same times (n = 15). The number of colony-forming units in left lung homogenate, evaluated at the end of the experiments, tended to be lower in PLV-treated animals than in controls (6.8 x 109 versus 6.4 x 1010 colony-forming units/g body weight; p = 0.06). Comparison of these numbers with the colony-forming units injected at the beginning of the experiments revealed a reduction in bacterial number in the PLV group and proliferation in the controls (-2.2 x 108 versus +5.6 x 1010 colony-forming units/g body weight; p < 0.05). Histologic examination demonstrated less inflammation and more homogeneous lung expansion in PLV-treated animals. Two animals in the PLV group had focal interstitial emphysema. Our results suggest that PLV with PF 5080 reduces bacterial proliferation in experimental group B streptococcal pneumonia.
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Affiliation(s)
- Mario Rudiger
- Department of Surgical Sciences, Karolinska Hospital, Huddinge University Hospital, Stockholm, Sweden. Germany
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Gregor T, Schmalisch G, Burkhardt W, Proquitté H, Wauer RR, Rüdiger M. Aerosolization of perfluorocarbons during mechanical ventilation: an in vitro study. Intensive Care Med 2003; 29:1354-60. [PMID: 12698244 DOI: 10.1007/s00134-003-1733-z] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2002] [Accepted: 02/21/2003] [Indexed: 11/28/2022]
Abstract
OBJECTIVE Inhalation of perfluorocarbons (PFC) has been suggested as a new and promising technique of PFC delivery in animal models of severe lung injury. However, no in vitro data were available on the efficacy of PFC aerosolization during mechanical ventilation. Therefore, the aim of the in vitro study was to investigate the influence of physical properties of PFC and the ventilatory settings on the amount of PFC delivered into the lung. DESIGN In vitro lung model study. SETTING University research laboratory. MEASUREMENTS AND RESULTS Two different PFC (PF 5080 and PFOB) were aerosolized with a PariBoy jet nebulizer. Using a PFC selective adsorber, the effect of endotracheal tube size (2 mm and 3 mm diameter) on delivery of PFC was investigated. PFC delivery was estimated by continuous measurement of weight gain of the adsorber (adsorption rate). Finally, the influence of respiratory rate and tidal volume on adsorption rate (AR) was studied. AR was significantly reduced by a decreasing tube diameter and ranged from 1.45+/-0.03 ml/min (no tube) to 0.93+/-0.03 ml/min (2.0 mm) for PF 5080 (vapor pressure 51 mmHg) and from 0.49+/-0.06 ml/min to 0.32+/-0.04 ml/min for PFOB (11 mmHg). PFC-aerosolization into a ventilatory circuit with simulation of spontaneous tidal breathing (minute volume 600 ml) reduced AR to 0.16+/-0.02 ml/min. During mechanical ventilation, changes in respiratory rate and tidal volume, which reduce minute ventilation, caused a decrease in AR. CONCLUSION The amount of PFC that can be delivered into the lung by aerosolization is very small and is influenced by PFC properties, tube size, and ventilatory settings.
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Affiliation(s)
- Tobias Gregor
- Clinic for neonatology, Charité Campus Mitte, Schumannstrasse 21, 10098, Berlin, Germany
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Rüdiger M, Wissel H, Ochs M, Burkhardt W, Proquitté H, Wauer RR, Stevens P, Rüstow B. Perfluorocarbons are taken up by isolated type II pneumocytes and influence its lipid synthesis and secretion. Crit Care Med 2003; 31:1190-6. [PMID: 12682492 DOI: 10.1097/01.ccm.0000060008.96029.7d] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
OBJECTIVE Because alveoli fill with perfluorocarbons during liquid ventilation, an uptake of perfluorocarbons by type II pneumocytes can be postulated that might affect synthesis and secretion of pulmonary surfactant. The study was performed to answer the following questions: Do isolated type II pneumocytes take up perfluorocarbons? Do perfluorocarbons affect lipid synthesis of type II cells? Do perfluorocarbons change surfactant secretion of type II pneumocytes? DESIGN Controlled experiments that used isolated type II pneumocytes. SETTING Experimental laboratory of a university hospital. SUBJECTS Male Wistar rats. INTERVENTIONS To study perfluorocarbon uptake, isolated type II cells were incubated with fluorescence-labeled perfluorocarbons and examined with a laser scanning microscope. The effect of perfluorocarbons on biosynthesis of phospholipids and triglycerides was measured by incubating cells that were pulse-labeled with [H]-palmitic acid for 30 secs, with two different perfluorocarbons (PF 5080 or RM 101) for 10 mins. The effect of perfluorocarbon incubation on lipid secretion was studied by transmission electron microscopy. To quantify secretion, adherent type II pneumocytes (containing radioactively labeled phospholipids) were incubated with perfluorocarbons, and extra- and intracellular radioactivity was measured. MEASUREMENTS AND MAIN RESULTS We found a significant uptake of labeled perfluorocarbons into lamellar bodies within 10 mins. Both perfluorocarbon species significantly (p <.05) reduced the biosynthesis of phospholipids when compared with control. Perfluorocarbon incubation did not affect mitochondrial activity, tested by MitoTracker staining. Transmission electron microscopy revealed changes that suggest an increased secretion of surfactant by type II cells. Studies with radioactively labeled surfactant revealed a significantly (p <.01) higher amount of extracellular lipids after RM 101 and PF 5080 treatment (RM 101, 17 +/- 7.9%; PF 5080, 9 +/- 1.9%) compared with control (5.3 +/- 1.9%). CONCLUSIONS Our results suggest that perfluorocarbons are taken up by type II pneumocytes and cause an increased secretion of surfactant, despite a relative reduction in the synthesis of phospholipids.
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Affiliation(s)
- Mario Rüdiger
- Clinic for Neonatology, Charité-Mitte, Humboldt-University Berlin, Germany
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