Absorption of amniotic fluid by amniochorion in sheep

J. Job Faber, Debra Anderson

    Research output: Contribution to journalArticle

    37 Citations (Scopus)

    Abstract

    Swallowing of amniotic fluid and lung fluid inflow were eliminated in 10 chronically instrumented fetuses. The urachus was ligated, and fetal was urine drained to the outside. At the beginning and the end of 21 experiments of 66 ± 5 (SE) h duration, all amniotic fluid was temporarily drained to the outside for volume measurement and sampling. Amniotic fluid osmolalities and oncotic pressures were experimentally controlled. Amniochorionic absorption of amniotic fluid depended strongly on the osmolality difference between amniotic fluid and fetal plasma (P <0.001), but at zero osmolality difference there still was a mean absorption rate of 23.8 ± 4.7 (SE) ml/h (P <0.001). Absorption was unaffected by the protein concentration difference between amniotic fluid and fetal plasma, but infused bovine albumin in the amniotic fluid was absorbed at a rate of 1.8 ± 0.4 g/h (P <0.001), corresponding to a volume flow of fluid of 33.8 ± 6.1 ml/h (P <0.001). Fluid absorption in the amniochorion is driven in part by crystalloid osmotic pressure, but about 25 ml/h is absorbed by a path that is permeable to protein. That path has the physiological characteristics of lymphatic drainage, although no anatomic basis is known to exist for a lymphatic system in the amniochorion.

    Original languageEnglish (US)
    JournalAmerican Journal of Physiology - Heart and Circulatory Physiology
    Volume282
    Issue number3 51-3
    StatePublished - 2002

    Fingerprint

    Amniotic Fluid
    Sheep
    Osmolar Concentration
    Urachus
    Lymphatic System
    Osmotic Pressure
    Deglutition
    Drainage
    Albumins
    Proteins
    Fetus
    Urine
    Pressure
    Lung

    Keywords

    • Lymphatics
    • Oncotic pressure
    • Volume homeostasis

    ASJC Scopus subject areas

    • Physiology

    Cite this

    Absorption of amniotic fluid by amniochorion in sheep. / Faber, J. Job; Anderson, Debra.

    In: American Journal of Physiology - Heart and Circulatory Physiology, Vol. 282, No. 3 51-3, 2002.

    Research output: Contribution to journalArticle

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