| Impact of surface tension on the conversion rate of large to small surfactant aggregates. | |
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MedLine Citation:
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PMID: 12834841 Owner: NLM Status: MEDLINE |
Abstract/OtherAbstract:
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The extracellular alveolar surfactant can be separated into the highly surface active large surfactant aggregates (LA) and the less active small surfactant aggregates (SA). Conversion of LA to SA is encountered upon cyclic surface area changes and demands the presence of enzymatic activity. In the present study we investigated the influence of surface tension on the conversion of LA to SA. Bronchoalveolar lavage fluid (BALF) obtained from healthy rabbits was cycled for various time periods in absence or presence of increasing amounts of serum proteins or oleic acid. LA were isolated, quantified and the minimum surface tension (gamma(min)) of uncycled or cycled LA was assessed in absence or presence of increasing amounts of serum proteins or oleic acid. In additional experiments, already cycled LA with a gamma(min) of approximately 20 mN/m were pooled, diluted to a similar PL concentration as original BALF and cycled a second time. Serum proteins and oleic acid dose-dependently: (i) increased the gamma(min) values of LA when added to the isolated LA; and (ii) decreased the LA to SA conversion when added to BALF. These events were directly correlated, suggesting inhibition of LA to SA conversion by increase in gamma(min) of the LA fraction. In line with this suggestion, already cycled LA displaying poor surface activity showed no further conversion in a second cycling maneuver, whereas LA being similarly prepared from uncycled BALF did. We conclude that LA to SA conversion is inversely correlated with the surface tension of the LA fraction. An increase in gamma(min) of the LA fraction during the cycling procedure blocks further LA to SA conversion and may thus represent a negative feedback mechanism. |
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Authors:
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Clemens Ruppert; Carolin Pucker; Philipp Markart; Kerstin Seibold; Ariane Bagheri; Fritz Grimminger; Werner Seeger; Andreas Günther |
Publication Detail:
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Type: Journal Article; Research Support, Non-U.S. Gov't |
Journal Detail:
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Title: Biophysical chemistry Volume: 104 ISSN: 0301-4622 ISO Abbreviation: Biophys. Chem. Publication Date: 2003 May |
Date Detail:
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Created Date: 2003-07-01 Completed Date: 2004-11-06 Revised Date: 2006-11-15 |
Medline Journal Info:
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Nlm Unique ID: 0403171 Medline TA: Biophys Chem Country: Netherlands |
Other Details:
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Languages: eng Pagination: 229-38 Citation Subset: IM |
Affiliation:
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Department of Internal Medicine, Medizinische Klinik II, Justus-Liebig University Giessen, 35385 Giessen, Germany. |
Export Citation:
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| MeSH Terms | |
Descriptor/Qualifier:
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Animals Blood Proteins / chemistry Bronchoalveolar Lavage Fluid / chemistry* Carboxylesterase / chemistry Oleic Acid / chemistry Particle Size Phospholipids / chemistry Pulmonary Surfactants / chemistry* Rabbits Surface Tension |
| Chemical | |
Reg. No./Substance:
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0/Blood Proteins; 0/Phospholipids; 0/Pulmonary Surfactants; 112-80-1/Oleic Acid; EC 3.1.1.1/Carboxylesterase |
From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine
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