The effect of methylation of phosphatidylethanolamine on the behaviour of lipid monolayers at the air–water interface

1988 ◽  
Vol 66 (5) ◽  
pp. 405-417 ◽  
Author(s):  
K. M. W. Keough ◽  
M. W. Hawco ◽  
C. S. Parsons
Keyword(s):  
Surface Tension ◽  
Dynamic Compression ◽  
High Surface ◽  
Head Group ◽  
Surface Tensions ◽  
Minimum Surface ◽  
Ideal Mixing ◽  
Compression And Expansion ◽  
Minimum Surface Tension ◽  
Mixed Systems

Monolayers of DPPE and its N-methylated derivatives including DPPC have been investigated at 23 and 37 °C using a modified Langmuir–Wilhelmy surface balance. The monolayers have been subjected to dynamic compression and expansion, and some characteristics of the surfaces have been determined. The minimum surface tension attained by surfaces containing the lipids (maximum surface pressures sustained by the films) depended on the extent of methylation of the head group. Monolayers of DPPE or N-MeDPPE collapsed at surface tensions of 12–16 mN∙m−1, whereas those containing N,N-diMeDPPE and DPPC could be compressed to near zero surface tension. The areas per molecule occupied by these lipids under high compression varied slightly and not systematically with head-group methylation. Monolayers containing mixtures of DPPC and DPPE were also studied under the same conditions. The monolayers showed some deviation from the behaviour expected if they were to have characteristics of ideally mixed systems. The minimum surface tensions attained suggested that monolayers containing 50 mol% or more DPPC might be further enriched during compression by some selective exclusion of the DPPE. At high surface pressures, some positive deviations in nominal areas per molecule from that expected for ideal mixing were observed in the monolayers made with 50 mol% or more DPPC. These deviations might be caused by packing disruptions associated with the explosion of lipid from the films.

Mechanisms of peroxynitrite-induced injury to pulmonary surfactants

1993 ◽  
Vol 265 (6) ◽  
pp. L555-L564 ◽  
Author(s):  
I. Y. Haddad ◽  
H. Ischiropoulos ◽  
B. A. Holm ◽  
J. S. Beckman ◽  
J. R. Baker ◽  
...  
Keyword(s):  
Surface Tension ◽  
Dynamic Compression ◽  
Lung Surfactant ◽  
Thiobarbituric Acid ◽  
Surfactant Protein ◽  
Surfactant Proteins ◽  
Minimum Surface ◽  
Surfactant Protein B ◽  
Minimum Surface Tension ◽  
By Products

Activated alveolar macrophages secrete both nitric oxide and superoxide in the alveolar lining fluid which combine rapidly to form peroxynitrite, a potent oxidizing agent capable of damaging lipids and proteins in biological membranes. Peroxynitrite (1 mM) plus 100 microM Fe3+EDTA inhibited calf lung surfactant extract (CLSE) from reaching a minimum surface tension below 10 mN/m on dynamic compression. Peroxynitrite and its by-products reacted with the unsaturated lipid components of CLSE, as evidenced by the appearance of conjugated dienes and thiobarbituric acid products, and damaged all surfactant proteins. A mixture of the hydrophobic proteins [surfactant protein B (SP-B) and surfactant protein C (SP-C)] exposed to peroxynitrite became incapable of lowering phospholipid minimum surface tension on dynamic compression. Exposure of SP-A to peroxynitrite decreased its ability to cause lipid aggregation and to act synergistically with SP-B and SP-C in lowering surface tension of surfactant lipids. Western blot analysis of SP-A exposed to peroxynitrite was consistent with fragmentation and polymerization of the 28- to 36-kDa triplet band, and amino acid analysis revealed the presence of significant levels of 3-nitro-L-tyrosine. We conclude that peroxynitrite and its reactive intermediates inhibit pulmonary surfactant function by lipid peroxidation and damaging surfactant proteins.

Dependence of surfactant function on extracellular pH: mechanisms and modifications

1994 ◽  
Vol 76 (2) ◽  
pp. 657-662 ◽  
Author(s):  
I. Y. Haddad ◽  
B. A. Holm ◽  
L. Hlavaty ◽  
S. Matalon
Keyword(s):  
Surface Tension ◽  
Ph Value ◽  
Dynamic Compression ◽  
Lung Surfactant ◽  
Protein A ◽  
Lung Mechanics ◽  
Normal Lung ◽  
Surfactant Mixtures ◽  
Minimum Surface ◽  
Minimum Surface Tension

We investigated alterations in pH on the surface properties of natural lung surfactant and the calf lung surfactant extract (CLSE), suspended in 10 mM N-2-hydroxyethylpiperazine-N′-2-ethanesulfonic acid, using a pulsating bubble surfactometer. Increasing the pH value of the medium to > 7.4 decreased the ability of CLSE, but not of natural lung surfactant mixtures (2 mg phospholipid/ml), to achieve a low minimum surface tension during dynamic compression and enhanced their sensitivity to albumin inactivation. These detrimental effects on surface tension were reversed by addition of surfactant protein A (SP-A; 3% by weight) or by increasing the lipid concentration to 4 mg/ml. SP-A-induced lipid aggregation at pH 10 was not different than at pH 7.4. Alkalinization impaired the ability of CLSE to restore normal lung mechanics in excised surfactant-deficient rats lungs. These results indicate that cooperation between SP-A and the hydrophobic surfactant proteins has an important role in achieving low minimum surface tension at pH > or = 7.6.

Interactions between plasma proteins and pulmonary surfactant: surface balance studies

1988 ◽  
Vol 66 (9) ◽  
pp. 1166-1173 ◽  
Author(s):  
Kevin M. W. Keough ◽  
Caroline S. Parsons ◽  
P. Terence Phang ◽  
Martin G. Tweeddale
Keyword(s):  
Surface Tension ◽  
Plasma Proteins ◽  
Pulmonary Surfactant ◽  
Dynamic Compression ◽  
Rate Of Change ◽  
Surfactant Monolayers ◽  
Human Fibrinogen ◽  
Compression And Expansion ◽  
Minimum Surface Tension ◽  
Surfactant Lipid

The influence of human fibrinogen, α-globulin, and albumin on the properties of monolayers of pulmonary surfactant under dynamic compression and expansion has been studied at 37 °C. Each of the proteins altered some of the properties of the normal compression and expansion isotherms of surfactant such that characteristics deemed desirable for proper lung function were impaired. The order of potency of these effects was fibrinogen>globulin>albumin. The proteins (a) decreased the maximum surface pressure (equivalent to the minimum surface tension) which the surfactant monolayers attained on compression, (b) decreased the areas occupied per mole of lipid phosphorus when the monolayers were at surface tensions of 20 and 12 mN∙m−1, (c) reduced the areas of the hysteresis between compression and expansion isotherms, and (d) decreased the rate of change of surface tension with area at the point of initial expansion of the monolayers. The proteins might compete with surfactant lipid for available space at the interface, especially at low film compression. They might also enhance the desorption of lipid from the monolayer. The findings are consistent with the loss of pulmonary function and presence of edema that occur in adult respiratory distress syndrome being contributed to by plasma proteins interfering with surfactant function.

Preparation and Properties of Amide Surfactants

2012 ◽  
Vol 550-553 ◽  
pp. 99-102
Author(s):  
Bao Cai Xu ◽  
Gui Ju Zhang ◽  
Yun Xia Li ◽  
Lu Cui
Keyword(s):  
Surface Tension ◽  
Critical Micelle Concentration ◽  
Aqueous Solutions ◽  
Surface Activity ◽  
Surface Tensions ◽  
Equilibrium Surface ◽  
Minimum Surface Tension ◽  
Dilute Aqueous Solutions ◽  
Lipophilic Groups ◽  
Long Chain

Amide surfactants have modified structures with lipophilic groups connecting hydrophilic groups through amido bond. The preparation of three families of amide surfactants including long chain N-acyl sarcosinates, amidopropyl dimethyl hydroxypropyl sulfobetaines and lauryl amidopropyl trimethyl ammoniums were discussed. The study of the surface activity of these compounds by measuring the equilibrium surface tensions of their dilute aqueous solutions were described. The minimum surface tension and the critical micelle concentration values of these compounds are given.

Effects of fixatives on function of pulmonary surfactant

2002 ◽  
Vol 93 (3) ◽  
pp. 911-916 ◽  
Author(s):  
H. Bachofen ◽  
U. Gerber ◽  
S. Schürch
Keyword(s):  
Surface Tension ◽  
Pulmonary Surfactant ◽  
Osmium Tetroxide ◽  
Uranyl Acetate ◽  
Film Stability ◽  
Minimum Surface ◽  
Natural Surfactant ◽  
Equilibrium Surface Tension ◽  
Minimum Surface Tension ◽  
Surface Active

The structure of pulmonary surfactant films remains ill defined. Although plausible film fragments have been imaged by electron microscopy, questions about the significance of the findings and even about the true fixability of surfactant films by the usual fixatives glutaraldehyde (GA), osmium tetroxide (OsO4), and uranyl acetate (UA) have not been settled. We exposed functioning natural surfactant films to fixatives within a captive bubble surfactometer and analyzed the effect of fixatives on surfactant function. The capacity of surfactant to reach near-zero minimum surface tension on film compression was barely impaired after exposure to GA or OsO4. Although neither GA nor OsO4 prevented the surfactant from forming a surface active film, GA increased the equilibrium surface tension to above 30 mN/m, and both GA and OsO4 decreased film stability as seen in the slowly rising minimum surface tension from 1 to ∼5 mN/m in 10 min. In contrast, the effect of UA seriously impaired surface activity in that both adsorption and minimum surface tension were substantially increased. In conclusion, the fixatives tested in this study are not suitable to fix, i.e., to solidify, surfactant films. Evidently, however, OsO4 and UA may serve as staining agents.

Effect of oxygen breathing at atmospheric pressure on pulmonary surfactant

1965 ◽  
Vol 20 (5) ◽  
pp. 855-858 ◽  
Author(s):  
Samuel T. Giammona ◽  
Donald Kerner ◽  
Stuart Bondurant
Keyword(s):  
Surface Tension ◽  
Atmospheric Pressure ◽  
Pulmonary Surfactant ◽  
Species Difference ◽  
Foam Fractionation ◽  
Minimum Surface ◽  
Oxygen Breathing ◽  
Minimum Surface Tension ◽  
Effect Of Oxygen

To evaluate the effects of oxygen breathing at atmospheric pressure on pulmonary surfactant, cats, rabbits, and rats were continuously kept in 98% oxygen until death occurred. Pulmonary surfactant was extracted by mincing of the lung and by foam fractionation of the lung. Surface tension of the extracts was measured on a Wilhelmy balance. Lung extracts prepared by both methods from the cats and rabbits kept in oxygen had greater surface tension than lung extracts from control animals. Surface tension of extracts prepared by foam fractionation of lungs of rats kept in oxygen did not differ from that of extracts of lungs of control rats, whereas surface tension of extracts prepared by mincing lungs of rats kept in oxygen had minimum surface tension greater than that of lung extracts of control rats. This species difference in the effects of oxygen breathing on pulmonary surfactant may reflect a difference in the pathogenesis of oxygen intoxication. oxygen intoxication; surface tension Submitted on October 19, 1964

Molar Volume and Surface Tension of Molten LaCl3-KCl Mixtures

1987 ◽  
Vol 42 (7) ◽  
pp. 690-694 ◽  
Author(s):  
K. Igarashi
Keyword(s):  
Surface Tension ◽  
Surface Energy ◽  
Molar Volume ◽  
Composition Range ◽  
Unit Area ◽  
Surface Tensions ◽  
Molar Volumes ◽  
Pressure Method ◽  
Minimum Surface ◽  
Energy Of Mixing

Molar volumes and surface tensions of molten LaCl3-KCl mixtures were measured by dilatometry and the maxim um bubble pressure method, respectively. The molar volume isotherms were found to deviate positively from additivity over the whole composition range, with the maxim um deviation at ca. 30 mol% LaCl3. At the same concentration the isotherms of surface tension at temperatures below 950 °C show a minimum . Surface energy of mixing per unit area calculated from the surface tensions shows a large negative excess at the corresponding composition. These observations are related to the existence o f LaCl63- in the KCl-rich melt.

Swim-bladder surfactants of Amazon air-breathing fishes

1978 ◽  
Vol 56 (4) ◽  
pp. 946-952 ◽  
Author(s):  
C. F. Phleger ◽  
B. S. Saunders
Keyword(s):  
Surface Tension ◽  
Lung Tissue ◽  
Phospholipid Composition ◽  
Vascular Supply ◽  
Swim Bladder ◽  
Tissue Slices ◽  
Minimum Surface ◽  
Arapaima Gigas ◽  
Minimum Surface Tension ◽  
Hoplerythrinus Unitaeniatus

Minimum surface tension and phospholipid composition of fish lung and swim-bladder wash and tissue extract were determined on an obligate water breather, Hoplias malabaricus, two species of facultative air breathers, Hoplerythrinus unitaeniatus and Erythrinus erythrinus, and two species of obligate air breathers, Arapaima gigas and Lepidosiren paradoxa. In addition, lung tissue slices were incubated with [1-14C]acetale and [1-14C]palmitate.All lung and swim-bladder wash lipid extracts showed a minimum surface tension of 20–25 dyn/cm (1 dyn = 10 μN). The principle phospholipid of all species is phosphatidylcholine; no phosphatidylglycerol was detected in any sample.The two obligate air breathers had higher rates of incorporation of isotope in tissue slices than facultative air breathers and nonair breathers. This observation correlates well with the greater vascular supply to their lungs.The phospholipid patterns of these fishes are significantly different from those of mammals. We speculate that these lipids recovered from saline wash may not be important in the maintenance of lung stability. Perhaps their function is keeping water from leaking into the lung and swim bladder.

Altered surface tension of lung extracts and lung mechanics

1965 ◽  
Vol 20 (6) ◽  
pp. 1253-1260 ◽  
Author(s):  
D. F. Tierney ◽  
R. P. Johnson
Keyword(s):  
Surface Tension ◽  
Phospholipase C ◽  
Transpulmonary Pressure ◽  
Lung Mechanics ◽  
Elastic Recoil ◽  
Rat Serum ◽  
Minimum Surface ◽  
Rat Lungs ◽  
Minimum Surface Tension ◽  
Volume Characteristics

Reduction of the surface area of 24 extracts of rabbit lungs by four-fifths decreased the surface tension to a minimum value of 0–5 dynes/cm at 18–22 C. However, minimum surface tension was above 15 dynes/cm if 1) the temperature was raised to 42 C, 2) the extract was prepared with distilled water, 3) phospholipase C was incubated with the extract, and 4) cholesterol or oleic acid was added to the surface. If blood or serum was added during the extraction, minimum surface tension was usually (although not invariably) elevated. Rinsing diluted rat serum or chylomicrons through the airways increases elastic recoil of excised rat lungs. Other reports show that heating a lung above 42 C or rinsing a solution of phospholipase C through the airways also increases elastic recoil of excised rat lungs. Therefore, these conditions alter the surface tension of lung extracts and the pressure-volume characteristics of the lungs concordantly. In addition, we found that the surface tension of lung extracts was not stable below 24 dynes/cm. Similar instability of the surface within the lung should lead to gradual atelectasis if a low transpulmonary pressure is maintained. elastic recoil; atelectasis; compliance; lung surface Submitted on January 21, 1965

Long-term cycling of surfactant films in Wilhelmy balance

1996 ◽  
Vol 8 (1) ◽  
pp. 173 ◽  
Author(s):  
B Sun ◽  
T Curstedt ◽  
B Robertson
Keyword(s):  
Surface Tension ◽  
Dependent Manner ◽  
Minimum Surface ◽  
Stable Period ◽  
Other Substances ◽  
Minimum Surface Tension ◽  
Surfactant Activity ◽  
Number Of Cycles ◽  
Dose Dependent

Surface properties of porcine surfactant were observed during long-term cycling in Wilhelmy balance. Various amounts of surfactant were applied onto the surface as dry particles or droplets, or were suspended in the hypophase, and the films generated by this material were subjected to 50% cyclic compression at a rate of 1 cycle per min. Film spreading was faster from a droplet than from a particle of lyophilized surfactant, but the 'stable period' during which minimum surface tension of the compressed film remained below 5 mN/m was significantly longer for the dry material. For surfactant suspensions the period of film 'refinement', defined as the number of cycles required to reduce minimum surface tension to a level below 5 mN/m, was inversely correlated with the concentration of surfactant in the hypophase. Thirteen batches of porcine surfactant, used successfully in clinical trials for treatment of neonatal respiratory distress syndrome, were evaluated in the same system suspended in the hypophase at a concentration of 0.5 mg/ml. Films adsorbed from these batches had a median refinement period of 4 cycles, and a median stable period of 2160 cycles (36 h). In the same assay system, surfactant activity was inhibited in a dose-dependent manner by serum, fibrinogen, meconium, and bilirubin, but the specific inhibitory activity was significantly higher for bilirubin than for the other substances tested.

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