State of the surface activity of rat lung surfactant at various times after left-sided pneumonectomy

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.

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Effect of triiodothyronine augmentation on rat lung surfactant phospholipids during sepsis

Journal of Applied Physiology ◽

10.1152/jappl.1997.82.6.2020 ◽

1997 ◽

Vol 82 (6) ◽

pp. 2020-2027 ◽

Cited By ~ 11

Author(s):

Sergey M. Ksenzenko ◽

Scott B. Davidson ◽

Amer A. Saba ◽

Alexander P. Franko ◽

Aml M. Raafat ◽

...

Keyword(s):

Lung Surfactant ◽

Cecal Ligation ◽

Active Role ◽

Lung Compliance ◽

Rat Lung ◽

Sprague Dawley ◽

Surfactant Phospholipids ◽

Surfactant Composition ◽

And Function

Ksenzenko, Sergey M., Scott B. Davidson, Amer A. Saba, Alexander P. Franko, Aml M. Raafat, Lawrence N. Diebel, and Scott A. Dulchavsky. Effect of triiodothyronine augmentation on rat lung surfactant phospholipids during sepsis. J. Appl. Physiol. 82(6): 2020–2027, 1997.—Surfactant functional effectiveness is dependent on phospholipid compositional integrity; sepsis decreases this through an undefined mechanism. Sepsis-induced hypothyroidism is commensurate and may be related. This study examines the effect of 3,3′,5-triiodo-l-thyronine (T3) supplementation on surfactant composition and function during sepsis. Male Sprague-Dawley rats underwent sham laparotomy (Sham) or cecal ligation and puncture (CLP) with or without T3supplementation [CLP/T3 (3 ng/h)]. After 6, 12, or 24 h, surfactant was obtained by lavage. Function was assessed by a pulsating bubble surfactometer and in vivo compliance studies. Sepsis produced a decrease in surfactant phosphatidylglycerol and phosphatidic acid, with an increase in lesser surface-active lipids phosphatidylserine and phosphatidylinositol. Phosphatidylcholine content was not significantly changed. Sepsis caused an alteration in the fatty acid composition and an increase in saturation in most phospholipids. Hormonal replacement attenuated these changes. Lung compliance and surfactant adsorption were reduced by sepsis and maintained by T3treatment. Thyroid hormone may have an active role in lung functional preservation through maintenance of surfactant homeostasis during sepsis.

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Interaction of transferrin saturated with iron with lung surfactant in respiratory failure

Journal of Applied Physiology ◽

10.1152/jappl.1994.77.2.757 ◽

1994 ◽

Vol 77 (2) ◽

pp. 757-766 ◽

Cited By ~ 16

Author(s):

M. Hallman ◽

A. Sarnesto ◽

K. Bry

Keyword(s):

Respiratory Failure ◽

Surface Activity ◽

Lung Surfactant ◽

Protein A ◽

Surfactant Protein ◽

Lung Damage ◽

Epithelial Lining ◽

Surface Absorption ◽

Epithelial Lining Fluid

Proteins that decrease the surface activity of surfactant accumulate in epithelial lining fluid in respiratory failure. The aim of this study was to isolate a surfactant inhibitor from the airways of rabbits in acute respiratory failure induced by bronchoalveolar lavage (BAL). This inhibitor was identified as being transferrin (TF). Unlike serum TF, TF recovered in respiratory failure was saturated with iron (Fe(3+)-TF). Fe(3+)-TF decreased the surface activity of normal surfactant in vitro, whereas iron-free TF had no effect. In the presence of H2O2 and a reducing agent, Fe(+3)-TF inactivated the surfactant complex: the surface absorption rate was decreased, immunoreactive surfactant protein A was decreased, and malondialdehyde was formed. The acute effects of Fe(3+)-TF and iron-free TF applied to the airways were studied in animal models. In respiratory failure induced by BAL, Fe(3+)-TF deteriorated respiratory failure, whereas iron-free TF had no effect. In respiratory failure induced by hyperoxia for 48 h, administration of iron-free TF ameliorated the respiratory failure and improved the surface activity in BAL. We propose that Fe(3+)-TF accumulating in epithelial lining fluid during lung damage contributes to surfactant inhibition and promotes the formation of free radicals that inactivate the surfactant system.

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Surface activity of a synthetic lung surfactant containing a phospholipase-resistant phosphonolipid analog of dipalmitoyl phosphatidylcholine

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.00346.2002 ◽

2003 ◽

Vol 285 (3) ◽

pp. L550-L559 ◽

Cited By ~ 16

Author(s):

Z. Wang ◽

A. L. Schwan ◽

L. L. Lairson ◽

J. S. O'Donnell ◽

G. F. Byrne ◽

...

Keyword(s):

Serum Albumin ◽

Surface Activity ◽

Dynamic Compression ◽

Lung Surfactant ◽

Dynamic Surface Tension ◽

Surfactant Proteins ◽

Chemical Degradation ◽

Dynamic Surface ◽

Dipalmitoyl Phosphatidylcholine ◽

Surfactant Dysfunction

Surface activity and sensitivity to inhibition from phospholipase A2 (PLA2), lysophosphatidylcholine (LPC), and serum albumin were studied for a synthetic C16:0 diether phosphonolipid (DEPN-8) combined with 1.5% by weight of mixed hydrophobic surfactant proteins (SP)-B/C purified from calf lung surfactant extract (CLSE). Pure DEPN-8 had better adsorption and film respreading than the major lung surfactant phospholipid dipalmitoyl phosphatidylcholine and reached minimum surface tensions <1 mN/m under dynamic compression on the Wilhelmy balance and on a pulsating bubble surfactometer (37°C, 20 cycles/min, 50% area compression). DEPN-8 + 1.5% SP-B/C exhibited even greater adsorption and had overall dynamic surface tension lowering equal to CLSE on the bubble. In addition, films of DEPN-8 + 1.5% SP-B/C on the Wilhelmy balance had better respreading than CLSE after seven (but not two) cycles of compression-expansion at 23°C. DEPN-8 is structurally resistant to degradation by PLA2, and DEPN-8 + 1.5% SP-B/C maintained high adsorption and dynamic surface activity in the presence of this enzyme. Incubation of CLSE with PLA2 led to chemical degradation, generation of LPC, and reduced surface activity. DEPN-8 + 1.5% SP-B/C was also more resistant than CLSE to direct biophysical inhibition by LPC, and the two were similar in their sensitivity to biophysical inhibition by serum albumin. These findings indicate that synthetic surfactants containing DEPN-8 combined with surfactant proteins or related synthetic peptides have potential utility for treating surfactant dysfunction in inflammatory lung injury.

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Clot-embedded natural surfactant: kinetics of fibrinolysis and surface activity

AJP Lung Cellular and Molecular Physiology ◽

10.1152/ajplung.1994.267.5.l618 ◽

1994 ◽

Vol 267 (5) ◽

pp. L618-L624 ◽

Cited By ~ 3

Author(s):

A. Gunther ◽

M. Kalinowski ◽

A. Elssner ◽

W. Seeger

Keyword(s):

Surface Activity ◽

Polyacrylamide Gel Electrophoresis ◽

Lung Surfactant ◽

Sodium Dodecyl ◽

Fibrin Clot ◽

Clot Lysis ◽

Dependent Manner ◽

Natural Surfactant ◽

Clot Material ◽

Kinetics Of

Polymerization of fibrin in the presence of pulmonary surfactant was recently noted to induce incorporation of phospholipids into the insoluble clot material, thereby effecting severe loss of surface activity (W. Seeger, A. Elssner, A. Gunther, H.-J. Kramer, and H. O. Kalinowski. Am. J. Respir. Cell Mol. Biol. 9: 213'220, 1993). In the present study, we investigated the influence of such incorporation of calf lung surfactant extract (CLSE) on the enzymatic cleavage of the fibrin network with the use of plasmin, trypsin, or elastase. Employing a fibrin-plate assay, the proteolytic release of radioactivity originating from 125I-labeled fibrinogen was assessed, and the pattern of split products was characterized by sodium dodecyl sulfate-polyacrylamide gel electrophoresis technique. Surface activity of CLSE was measured in the pulsating bubble surfactometer. When incorporated into the fibrin clot, CLSE inhibited the cleavage of fibrin by all proteases in a dose-dependent manner without affecting the profile of scission products. Inhibition of plasmin-induced clot lysis was also noted on incorporation of CLSE into clotted plasma and on incorporation of dipalmitoylphosphatidylcholine into fibrin polymers. In contrast, corresponding concentrations of CLSE added to the incubation medium after preformation of the fibrin matrix did not substantially influence the kinetics of fibrinolysis. CLSE incorporation into the nascent fibrin clot resulted in complete loss of surface activity, but adsorption and surface tension-lowering properties were largely restored by subsequent plasmic clot lysis. Arising fibrin split products were shown to display similar inhibitory strength on CLSE surface activity compared with fibrinogen split products.(ABSTRACT TRUNCATED AT 250 WORDS

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