Document Detail


The association between meconium and the production and reabsorption of lung liquid and lactate loss by in vitro lungs from fetal guinea pigs.
MedLine Citation:
PMID:  10920338     Owner:  NLM     Status:  MEDLINE    
Abstract/OtherAbstract:
OBJECTIVE: We sought to use an in vitro approach to determine relationships between meconium and fetal lung liquid production and to relate meconium to possible problems in lung liquid removal at birth. STUDY DESIGN: Near-term fetal guinea pigs were divided according to the level of spontaneously occurring meconium (no meconium, light meconium, or heavy meconium). Their lungs were maintained in vitro in Krebs-Henseleit saline solution for 3 hours. Lung liquid production or reabsorption was measured by a dye-dilution method, and loss of lactate to the lung liquid and outer Krebs-Henseleit solution was monitored. Reabsorptions were investigated by activating powerful responses with dinitrophenol during the middle hour. RESULTS: During the first hour, lungs from meconium-free fetuses produced liquid at 1.25 +/- 0.12 mL/kg(-1) body weight. h(-1); rates from light or heavy meconium groups were not significantly different (n = 18). Similarly, total lactate loss was not significantly different between the meconium-free and light-meconium groups but was twice as high in heavy-meconium preparations (73.68 +/- 10.60 micromol/L. g(-1) dry lung tissue. h(-1); P <.025, analysis of variance). The meconium-free and heavy-meconium groups continued to produce fluid, with no significant change throughout the 3 hours of incubation; lactate losses fell slightly. Therefore there were no problems with fluid production with meconium present, but the high-lactate losses with heavy meconium suggested long-term intrauterine hypoxia. Dinitrophenol produced powerful reabsorptions in lungs from meconium-free fetuses (-0.85 +/- 0.35 mL. kg(-1) body weight. h(-1); P <.005, analysis of variance; P <.0005, regression analysis) but failed to do so in heavy-meconium fetuses (n = 36). Lactate losses rose 2-fold in both groups (P <.005 to P < 0.0005, analysis of variance and regression analysis), despite already elevated losses with heavy meconium (n = 12). Therefore, in heavy-meconium fetuses, dinitrophenol affected metabolic pathways but did not activate fluid reabsorption, suggesting damage to reabsorptive mechanisms. CONCLUSION: Unless major airways are blocked, meconium is not associated with reduced fetal lung liquid production, which can cause poor lung development, but there may well be poor fluid removal after birth because of compromised reabsorptive mechanisms, which are unlikely to be helped by possible hormonal intervention.
Authors:
B A Chua; L Chan; P M Kindler; A M Perks
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Publication Detail:
Type:  In Vitro; Journal Article; Research Support, Non-U.S. Gov't    
Journal Detail:
Title:  American journal of obstetrics and gynecology     Volume:  183     ISSN:  0002-9378     ISO Abbreviation:  Am. J. Obstet. Gynecol.     Publication Date:  2000 Jul 
Date Detail:
Created Date:  2000-08-24     Completed Date:  2000-08-24     Revised Date:  2006-11-15    
Medline Journal Info:
Nlm Unique ID:  0370476     Medline TA:  Am J Obstet Gynecol     Country:  UNITED STATES    
Other Details:
Languages:  eng     Pagination:  235-44     Citation Subset:  AIM; IM    
Affiliation:
Departments of Obstetrics and Gynecology and Zoology, University of British Columbia, Vancouver, Canada.
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MeSH Terms
Descriptor/Qualifier:
Absorption
Animals
Body Fluids / physiology*
Dinitrophenols / pharmacology
Female
Fetal Hypoxia / diagnosis
Guinea Pigs
Kinetics
Lactic Acid / blood*
Lung / drug effects,  embryology*,  physiology*
Meconium*
Pregnancy
Regression Analysis
Chemical
Reg. No./Substance:
0/Dinitrophenols; 50-21-5/Lactic Acid

From MEDLINE®/PubMed®, a database of the U.S. National Library of Medicine


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