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.

Disparity between tidal and static volumes of immature lungs treated with reconstituted surfactants

1996 ◽  
Vol 80 (1) ◽  
pp. 62-68 ◽  
Author(s):  
T. Kobayashi ◽  
W. Z. Li ◽  
K. Tashiro ◽  
R. Takahashi ◽  
Y. Waseda ◽  
...  
Keyword(s):  
Surface Tension ◽  
Pulmonary Surfactant ◽  
Static Pressure ◽  
Surfactant Adsorption ◽  
Minimum Surface ◽  
Natural Surfactant ◽  
Minimum Surface Tension ◽  
Volume Measurements ◽  
Porcine Lungs

We biologically assessed functions of several reconstituted surfactants with the same minimum surface tension (2-3 mN/m) as “complete” porcine pulmonary surfactant (natural surfactant) but with longer surface adsorption times. Administration of natural surfactant (adsorption time 0.29 s) into the lungs of surfactant-deficient immature rabbits brought a tidal volume of 16.1 +/- 4.4 (SD) ml/kg during mechanical ventilation with 40 breaths/min and 20 cmH2O insufflation pressure. In static pressure-volume recordings, these animals showed a lung volume of 62.4 +/- 9.7 ml/kg at 30 cmH2O airway pressure and maintained 55% of this volume when the pressure decreased to 5 cmH2O. With two reconstituted surfactants consisting of synthetic lipids or isolated lipids from porcine lungs plus surfactant-associated hydrophobic proteins (adsorption times 0.57 and 0.78 s, respectively), tidal volumes were < 38% of that with natural surfactant (P < 0.05), but static pressure-volume recordings were not different. Care is therefore needed in estimating the in vivo function of surfactant preparations from minimum surface tension or static pressure-volume measurements.

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

Effect of artificial surfactant on pulmonary function in preterm and full-term lambs

1990 ◽  
Vol 69 (2) ◽  
pp. 465-472 ◽  
Author(s):  
I. M. Gladstone ◽  
A. O. Ray ◽  
C. M. Salafia ◽  
J. Perez-Fontan ◽  
M. R. Mercurio ◽  
...  
Keyword(s):  
Surface Tension ◽  
Functional Residual Capacity ◽  
Dynamic Compliance ◽  
Full Term ◽  
Tween 20 ◽  
Minimum Surface ◽  
Natural Surfactant ◽  
Equilibrium Surface Tension ◽  
Lung Expansion ◽  
Residual Capacity

We hypothesized that agents very different from surfactant may still support lung function. To test this hypothesis, we instilled FC-100, a fluorocarbon, and Tween 20, a detergent, which have higher minimum surface tensions and less hysteresis than surfactant, into 15 full-term and 14 preterm lambs. FC-100 and Tween 20 were as efficient as natural surfactant in improving gas exchange and compliance in preterm lambs with respiratory failure. Dynamic compliance correlated with the equilibrium surface tension of the alveolar wash in both full-term (P less than 0.02) and preterm (P less than 0.008) lambs. Functional residual capacity in full-term and preterm lambs was lower after treatment with the two test agents than with surfactant, findings consistent with qualitative histology. Oxygenation in full-term lambs correlated with mean lung volumes (P less than 0.003), suggesting that the hysteresis and/or low minimum surface tension of surfactant may improve mean lung volume, and hence oxygenation, by maintaining functional residual capacity. The effects of the test agents suggest that agents with biophysical properties different from surfactant may still aid lung expansion.

scholarly journals Biophysical characterization and modeling of lung surfactant components

1999 ◽  
Vol 86 (5) ◽  
pp. 1702-1714 ◽  
Author(s):  
E. P. Ingenito ◽  
L. Mark ◽  
J. Morris ◽  
F. F. Espinosa ◽  
R. D. Kamm ◽  
...  
Keyword(s):  
Surface Tension ◽  
Neutral Lipid ◽  
Rate Coefficient ◽  
Lung Surfactant ◽  
Interfacial Area ◽  
Interfacial Behavior ◽  
Film Stability ◽  
Biophysical Characterization ◽  
Equilibrium Surface Tension ◽  
Minimum Surface Tension

The present study characterizes the dynamic interfacial properties of calf lung surfactant (CLS) and samples reconstituted in a stepwise fashion from phospholipid (PL), hydrophobic apoprotein (HA), surfactant apoprotein A (SP-A), and neutral lipid fractions. Dipalmitoylphosphatidylcholine (DPPC), the major PL component of surfactant, was examined for comparison. Surface tension was measured over a range of oscillation frequencies (1–100 cycles/min) and bulk phase concentrations (0.01–1 mg/ml) by using a pulsating bubble surfactometer. Distinct differences in behavior were seen between samples. These differences were interpreted by using a previously validated model of surfactant adsorption kinetics that describes function in terms of 1) adsorption rate coefficient ( k 1), 2) desorption rate coefficient ( k 2), 3) minimum equilibrium surface tension (γ*), 4) minimum surface tension at film collapse (γmin), and 5) change in surface tension with interfacial area for γ < γ* ( m 2). Results show that DPPC and PL have k 1 and k 2 values several orders of magnitude lower than CLS. PL had a γmin of 19–20 dyn/cm, significantly greater than CLS (nearly zero). Addition of the HA to PL restored dynamic interfacial behavior to nearly that of CLS. However, m 2 remained at a reduced level. Addition of the SP-A to PL + HA restored m 2 to a level similar to that of CLS. No further improvement in function occurred with the addition of the neutral lipid. These results support prior studies that show addition of HA to the PL markedly increases adsorption and film stability. However, SP-A is required to completely normalize dynamic behavior.

Surface tension and pulmonary compliance in premature rabbits

1989 ◽  
Vol 66 (5) ◽  
pp. 2039-2044 ◽  
Author(s):  
M. R. Mercurio ◽  
J. M. Fiascone ◽  
D. M. Lima ◽  
H. C. Jacobs
Keyword(s):  
Surface Tension ◽  
Surface Properties ◽  
Pulmonary Surfactant ◽  
Dynamic Compliance ◽  
Ringer Solution ◽  
Tween 20 ◽  
Adult Rabbit ◽  
Equilibrium Surface ◽  
Equilibrium Surface Tension ◽  
Pulmonary Compliance

In vitro surface properties of pulmonary surfactant thought to be essential to its ability to increase pulmonary compliance include minimum surface tension less than 10 dyn/cm and large surface tension variability and hysteresis. We tested four surface-active agents (Tween 20, a detergent; and FC-100, FC-430, and FC-431, industrial fluorocarbons), all lacking these properties, for their ability to increase pulmonary compliance in surfactant-deficient premature rabbits. Fetal rabbits were delivered by cesarean section at 27 days (full term = 31 days) and injected via tracheostomy with 50% lactated Ringer solution, adult rabbit surfactant, or one of the four experimental agents. Dynamic compliance was measured using 1 h of mechanical ventilation followed by alveolar lavage. Each experimental agent produced a dynamic compliance significantly higher than 50% lactated Ringer solution and statistically equal to or greater than natural surfactant. Equilibrium surface tension of the agents and minimum and equilibrium surface tension of the alveolar washes each correlated with compliance (P less than 0.05). This suggests that some surface properties of pulmonary surfactant believed to be essential are not, although surface tension does seem to play a role in pulmonary compliance.

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.

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.

scholarly journals ADSORPTION AND DILATIONAL RHEOLOGICAL PROPERTIES OF CHITOSAN LACTATE AT THE LIQUID-GAS INTERFACE

2020 ◽  
pp. 816-826
Author(s):  
Анна Игоревна Ковтун
Keyword(s):  
Molecular Weight ◽  
Surface Tension ◽  
Surface Elasticity ◽  
Rheological Characteristics ◽  
Drop Shape ◽  
Equilibrium Surface Tension ◽  
Viscoelastic Modulus ◽  
Surface Active ◽  
Adsorption Layers ◽  
Chitosan Lactate

Методом формы осциллирующей капли исследованы адсорбционные и дилатационные реологические характеристики (модуль упругости и вязкости) лактата хитозана на границе раздела жидкость - газ. Определены зависимости динамического и равновесного поверхностного натяжения от концентрации лактата хитозана в растворе. Установлено, что полученные зависимости сходны с таковыми для поверхностноактивных высокомолекулярных соединений. Изучены зависимости поверхностных упругости и вязкости лактата хитозана от частоты осцилляций и концентрации. Показано, что лактат хитозана способен образовывать упругие адсорбционные слои со значениями модуля вязкоупругости сопоставимыми для биополимеров белковой природы. The adsorption and dilatational rheological characteristics (the elasticity and viscosity modulus) of chitosan lactate at the liquid-gas interface are investigated by the oscillating drop shape method. The dependences of the dynamic and equilibrium surface tension on the concentration of chitosan lactate in solution have been determined. It was found that the dependences obtained are similar to those for surface-active high-molecular weight compounds. The dependences of the surface elasticity and viscosity of chitosan lactate on the oscillation frequency and concentration have been studied. It has been shown that chitosan lactate is capable of forming elastic adsorption layers with the values of the viscoelastic modulus comparable to that of protein biopolymers.

Dipalmitoyl lecithin: studies on surface properties

1965 ◽  
Vol 20 (4) ◽  
pp. 779-781 ◽  
Author(s):  
Marian C. Kuenzig ◽  
Robert W. Hamilton ◽  
Leonard F. Peltier
Keyword(s):  
Surface Tension ◽  
Pulmonary Surfactant ◽  
Surface Film ◽  
Ethanol Solution ◽  
Original Surface ◽  
Dipalmitoyl Lecithin ◽  
Minimum Surface Tension ◽  
Humidified Air ◽  
Surface Balance ◽  
Normal Lungs

A preparation of synthetic dipalmitoyl lecithin has been devised whose activity on a Wilhelmy surface balance is similar to that of extracts from normal lungs. An ethanol solution of lecithin is precipitated with albumin, and a drop of the suspension containing approximately 0.04 mg lecithin is spread on the surface of 0.9% NaCl in the trough of the balance. This preparation appears to be insensitive to oxidation and when run under humidified air gives reproducible results. It has a low minimum surface tension (5—10 dynes/cm) when compressed to 20% of the original surface area and exhibits considerable hysteresis on re-expansion. Addition of certain lipids to the surface film produces changes similar to those caused by addition of these lipids to cat lung extracts. surface tension; surface activity; pulmonary surfactant Submitted on September 8, 1964

Surfactant inactivation by hyperventilation: conservation by end-expiratory pressure

1975 ◽  
Vol 38 (3) ◽  
pp. 461-466 ◽  
Author(s):  
I. Wyszogrodski ◽  
K. Kyei-Aboagye ◽  
H. W. Taeusch ◽  
M. E. Avery
Keyword(s):  
Surface Tension ◽  
Specific Activity ◽  
Surface Film ◽  
Active Material ◽  
Positive End Expiratory Pressure ◽  
Elastic Recoil ◽  
Minimum Surface Tension ◽  
Surface Active ◽  
Film Balance ◽  
Surface Active Material

Hyperventilation, defined as repeated hyperinflations, for three hours in open-chested anesthetized cats increased elastic recoil and elevated minimum surface tension of lung extracts as measured on a surface film balance. Equivalent hyperventilation from an elevated lung volume did not alter the pressure-volume relationships. When a mixture of [3H]glycerol and [14C]palmitate had been injected 17 h before the three hour period of phyerventilation, an increase in the ratio of specific activity in wash to tissue lecithin occurred in the hyperventilated cats compared to controls. These findings suggest that hyperventilation promotes release of surface active material from tissue to alveolus, but the released material is inactivated. The application of 2.5 cmH2O positive end-expiratory pressure prevented the adverse effects of hyperventilation. The same increase in wash to tissue lecithin occurred during this study; since the material was appropriately surface active, we conclude that the positive end-expiratory pressure prevented its inactivation.

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