Investigations in vitro of the Influence of Gas Phase Factor on the Properties of the Pulmonary Surfactant

2015 ◽  
pp. 138-142
Author(s):  
J. Paweiek ◽  
M. Hanicka ◽  
E. Sowinska
Keyword(s):  
Gas Phase ◽  
Pulmonary Surfactant ◽  
Phase Factor

Phospholipase A2 is present in meconium and inhibits the activity of pulmonary surfactant: an in vitro study

2007 ◽  
Vol 90 (4) ◽  
pp. 412-416 ◽  
Author(s):  
AJJ Schrama ◽  
AJ Beaufort ◽  
YRM Sukul ◽  
SM Jansen ◽  
BJHM Poorthuis ◽  
...  
Keyword(s):  
Phospholipase A2 ◽  
Pulmonary Surfactant ◽  
In Vitro Study ◽  
Vitro Study

scholarly journals Rapid compressions in a captive bubble apparatus are isothermal

2003 ◽  
Vol 95 (5) ◽  
pp. 1896-1900
Author(s):  
Wenfei Yan ◽  
Stephen B. Hall
Keyword(s):  
Hydrostatic Pressure ◽  
Gas Phase ◽  
Pulmonary Surfactant ◽  
First Order ◽  
First Order Kinetics ◽  
Gas Phase Molecules ◽  
Actual Change ◽  
Phase Temperature ◽  
Two Phases ◽  
Interfacial Films

Captive bubbles are commonly used to determine how interfacial films of pulmonary surfactant respond to changes in surface area, achieved by varying hydrostatic pressure. Although assumed to be isothermal, the gas phase temperature (Tg) would increase by >100°C during compression from 1 to 3 atm if the process were adiabatic. To determine the actual change in temperature, we monitored pressure (P) and volume (V) during compressions lasting <1 s for bubbles with and without interfacial films and used P · V to evaluate Tg. P · V fell during and after the rapid compressions, consistent with reductions in n, the moles of gas phase molecules, because of increasing solubility in the subphase at higher P. As expected for a process with first-order kinetics, during 1 h after the rapid compression P · V decreased along a simple exponential curve. The temporal variation of n moles of gas was determined from P · V >10 min after the compression when the two phases should be isothermal. Back extrapolation of n then allowed calculation of Tg from P · V immediately after the compression. Our results indicate that for bubbles with or without interfacial films compressed to >3 atm within 1 s, the change in Tg is <2°C.

In vitro fertilisation of Chinese hamster oocytes by spermatozoa that have undergone ionophore A23187-induced acrosome reaction, and their subsequent development into blastocysts

Zygote ◽  
1996 ◽  
Vol 4 (2) ◽  
pp. 93-99 ◽  
Author(s):  
Hiroyuki Tateno ◽  
Yujiroh Kamiguchi
Keyword(s):  
Gas Phase ◽  
Acrosome Reaction ◽  
Chinese Hamster ◽  
Subsequent Development ◽  
In Vitro Fertilisation ◽  
Ionophore A23187 ◽  
Cell Stage ◽  
Developmental Arrest ◽  
Potential Use

SummaryTo enhance potential use of the Chinese hamster, Cricetulus griseus, in developmental and cytogenetic studies of mammalian gametes and embryos, techniques for in vitro fertilisation and embryo culture were developed in the species. Spermatozoa were recovered from the vasa deferentia of mature males, and incubated in modified TYH medium for 1 h at 37°C under 5% CO2 in air. They were then treated with ionophore A23187 (20¼M) for 10min to induce the acrosome reaction. Following ionophore treatment, superovulated oocytes were collected from hormonally stimulated females and incubated with the acrosome-reacted spermatozoa for 2 h at 37°C under 5% CO2 in air. In this study, 245 oocytes ova (98.0%) were determined to be monospermic. The monospermic ova were then cultured in TYH supplemented with 1mM hypotaurine under the same gas phase. Within 30h of fertilisation, 182 ova (93.8%) cleaved to the 2-cell stage, and subsequently 163 ova (84.0%) developed beyond the 2-cell stage. Thus, obstinate developmental arrest at the 2-cell stage(‘2-cell block’) was not observed in this species. Ultimately, 65.5% of monospermic ova reached morula to blastocyst stages.

scholarly journals The role of miR-431-5p in regulating pulmonary surfactant expression in vitro

2019 ◽  
Vol 24 (1) ◽  
Author(s):  
Shujun Li ◽  
Zhongyi Sun ◽  
Tao Chen ◽  
Jingjing Pan ◽  
Yanqing Shen ◽  
...  
Keyword(s):  
Pulmonary Surfactant

Identification of canine pulmonary surfactant-associated glycoprotein A precursors

1985 ◽  
Vol 58 (6) ◽  
pp. 2091-2095 ◽  
Author(s):  
T. E. Weaver ◽  
J. A. Whitsett ◽  
W. M. Hull ◽  
G. Ross
Keyword(s):  
Gel Electrophoresis ◽  
Pulmonary Surfactant ◽  
Polyacrylamide Gel Electrophoresis ◽  
Sodium Dodecyl ◽  
Surfactant Protein ◽  
Lung Lavage ◽  
Complex Carbohydrate ◽  
Monospecific Antiserum ◽  
Microsomal Membranes

Surfactant-associated glycoproteins A were identified by two-dimensional sodium dodecyl sulfate-polyacrylamide gel electrophoresis of crude surfactant from canine alveolar lavage: an unglycosylated form (protein A1), 27,000–28,000 daltons; glycoprotein A2, 32,000–34,000 daltons; and glycoprotein A3, 37,000–38,000 daltons; pH at isoelectric point (pI) 4.5–5.0. Glycoproteins A2 and A3 were electroeluted and used to prepare a monospecific antiserum that identified proteins A1, A2, and A3 in immunoblots of crude surfactant obtained from dog lung lavage. This antiserum precipitated several proteins from in vitro translated canine lung poly(A)+ mRNA; proteins of 27,000 daltons, pI 5.0, and 28,000 daltons, pI 4.8–5.0, which precisely comigrated with proteins A1 from canine surfactant. Cotranslational processing of the primary translation products by canine pancreatic microsomal membranes resulted in larger proteins of 31,000–34,000 daltons, pI 4.8–5.0. Treatment of these processed forms of glycoprotein A with endoglycosidase F, to remove N-linked carbohydrate, resulted in proteins of 27,000–28,000 daltons which precisely comigrated with surfactant protein A1. These observations demonstrate that the polypeptide precursors to the glycoproteins A complex are extensively modified by addition of asparagine N-linked complex carbohydrate and are subsequently secreted as glycoproteins A2 and A3.

Requirements for extracellular metabolism of pulmonary surfactant: tentative identification of serine protease

1992 ◽  
Vol 262 (4) ◽  
pp. L446-L453 ◽  
Author(s):  
N. J. Gross ◽  
R. M. Schultz
Keyword(s):  
Serine Protease ◽  
Surface Area ◽  
Pulmonary Surfactant ◽  
Lamellar Body ◽  
Alveolar Epithelium ◽  
Alveolar Type ◽  
Type Ii Cells ◽  
Type Ii ◽  
Ph Optimum

Pulmonary alveolar surfactant is secreted by the alveolar epithelium in the form of lamellar bodylike structures that evolve sequentially into tubular myelin and vesicular forms that can be separated by centrifugation. Using an in vitro procedure by which the extracellular metabolism of pulmonary surfactant can be mimicked, namely cyclic variation in surface area, we previously reported that serine protease activity, which we called “convertase,” was required for the conversion of tubular myelin to the vesicular form. In the present studies we explored the biochemical requirements of this activity and sought the enzyme in alveolar products. Convertase activity has unusual requirements; in addition to being dependent on repetitive variations in surface area (cycling), it requires the presence of a high g fraction of lung secretions that is heat stable and not inhibitable by diisopropyl fluorophosphate (DFP) or alpha 1-antitrypsin, both typical serine protease inhibitors. The enzyme does not require calcium ions and has a pH optimum of 7.4. Convertase appears to be a component of surfactant itself because the ability of purified surfactant to convert to the vesicular form on cycling is impaired by pretreating it with DFP. A protein of Mr 75,000 that reacts with DFP and is heat sensitive was found in alveolar lavage, lamellar body preparations, and lung homogenate. It copurifies with lung surfactant in sucrose gradients. A similar DFP-reactive protein was observed in stable human neoplastic peripheral airway cell lines that express type II properties, suggesting that it may be a product of type II cells. We tentatively conclude that surfactant convertase is a 75,000 serine protease that is closely associated with surfactant phospholipid and that may be a product of alveolar type II cells.

Alterations in the surface properties of lung surfactant in the torpid marsupial Sminthopsis crassicaudata

1998 ◽  
Vol 84 (1) ◽  
pp. 146-156 ◽  
Author(s):  
Olga V. Lopatko ◽  
Sandra Orgeig ◽  
Christopher B. Daniels ◽  
David Palmer
Keyword(s):  
Surface Tension ◽  
Surface Properties ◽  
Surface Activity ◽  
Pulmonary Surfactant ◽  
Lung Surfactant ◽  
Lung Compliance ◽  
Equilibrium Surface Tension ◽  
Sminthopsis Crassicaudata

Lopatko, Olga V., Sandra Orgeig, Christopher B. Daniels, and David Palmer. Alterations in the surface properties of lung surfactant in the torpid marsupial Sminthopsis crassicaudata. J. Appl. Physiol. 84(1): 146–156, 1998.—Torpor changes the composition of pulmonary surfactant (PS) in the dunnart Sminthopsis crassicaudata [C. Langman, S. Orgeig, and C. B. Daniels. Am. J. Physiol. 271 ( Regulatory Integrative Comp. Physiol. 40): R437–R445, 1996]. Here we investigated the surface activity of PS in vitro. Five micrograms of phospholipid per centimeter squared surface area of whole lavage (from mice or from warm-active, 4-, or 8-h torpid dunnarts) were applied dropwise onto the subphase of a Wilhelmy-Langmuir balance at 20°C and stabilized for 20 min. After 4 h of torpor, the adsorption rate increased, and equilibrium surface tension (STeq), minimal surface tension (STmin), and the %area compression required to achieve STmin decreased, compared with the warm-active group. After 8 h of torpor, STmin decreased [from 5.2 ± 0.3 to 4.1 ± 0.3 (SE) mN/m]; %area compression required to achieve STmindecreased (from 43.4 ± 1.0 to 27.4 ± 0.8); the rate of adsorption decreased; and STeqincreased (from 26.3 ± 0.5 to 38.6 ± 1.3 mN/m). ST-area isotherms of warm-active dunnarts and mice at 20°C had a shoulder on compression and a plateau on expansion. These disappeared on the isotherms of torpid dunnarts. Samples of whole lavage (from warm-active and 8-h torpor groups) containing 100 μg phospholipid/ml were studied by using a captive-bubble surfactometer at 37°C. After 8 h of torpor, STmin increased (from 6.4 ± 0.3 to 9.1 ± 0.3 mN/m) and %area compression decreased in the 2nd (from 88.6 ± 1.7 to 82.1 ± 2.0) and 3rd (from 89.1 ± 0.8 to 84.9 ± 1.8) compression-expansion cycles, compared with warm-active dunnarts. ST-area isotherms of warm-active dunnarts at 37°C did not have a shoulder on compression. This shoulder appeared on the isotherms of torpid dunnarts. In conclusion, there is a strong correlation between in vitro changes in surface activity and in vivo changes in lipid composition of PS during torpor, although static lung compliance remained unchanged (see Langman et al. cited above). Surfactant from torpid animals is more active at 20°C and less active at 37°C than that of warm-active animals, which may represent a respiratory adaptation to low body temperatures of torpid dunnarts.

CO binding to hemoglobin and myoglobin in equilibrium with a gas phase of low PO2 value

1988 ◽  
Vol 65 (6) ◽  
pp. 2513-2517 ◽  
Author(s):  
A. Agostoni ◽  
M. Perrella ◽  
L. Sabbioneda ◽  
U. Zoni
Keyword(s):  
Computer Simulation ◽  
Gas Phase ◽  
Qualitative Agreement ◽  
Significant Proportion ◽  
In Vitro System

The aim of this paper was to measure the binding of CO to myoglobin and hemoglobin at various PO2 values. For this purpose we have studied an "in vitro" system made up of solutions of hemoglobin and myoglobin equilibrated in two connected tonometers with the same gas phase of various PO2 and PCO. The results indicate that a significant proportion of CO is released by hemoglobin and binds myoglobin at low PO2 values (approximately 2-3 Torr), in qualitative agreement with the predictions of a previous computer simulation of the "in vivo" system.

scholarly journals Pulmonary surfactant inhibition of nanoparticle uptake by alveolar epithelial cells

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
M. Radiom ◽  
M. Sarkis ◽  
O. Brookes ◽  
E. K. Oikonomou ◽  
A. Baeza-Squiban ◽  
...  
Keyword(s):  
Epithelial Cells ◽  
Pulmonary Surfactant ◽  
Fluid Layer ◽  
Alveolar Epithelial Cell ◽  
Cell System ◽  
Engineered Nanoparticles ◽  
Alveolar Epithelial Cells ◽  
Alveolar Epithelial ◽  
Inhaled Nanoparticles

Abstract Pulmonary surfactant forms a sub-micrometer thick fluid layer that covers the surface of alveolar lumen and inhaled nanoparticles therefore come in to contact with surfactant prior to any interaction with epithelial cells. We investigate the role of the surfactant as a protective physical barrier by modeling the interactions using silica-Curosurf-alveolar epithelial cell system in vitro. Electron microscopy displays that the vesicles are preserved in the presence of nanoparticles while nanoparticle-lipid interaction leads to formation of mixed aggregates. Fluorescence microscopy reveals that the surfactant decreases the uptake of nanoparticles by up to two orders of magnitude in two models of alveolar epithelial cells, A549 and NCI-H441, irrespective of immersed culture on glass or air–liquid interface culture on transwell. Confocal microscopy corroborates the results by showing nanoparticle-lipid colocalization interacting with the cells. Our work thus supports the idea that pulmonary surfactant plays a protective role against inhaled nanoparticles. The effect of surfactant should therefore be considered in predictive assessment of nanoparticle toxicity or drug nanocarrier uptake. Models based on the one presented in this work may be used for preclinical tests with engineered nanoparticles.

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