Absence of fetal placental waterfall phenomenon in chronically prepared fetal lambs

Kent Thornburg, J. M. Bissonnette, J. J. Faber

    Research output: Chapter in Book/Report/Conference proceedingChapter

    9 Citations (Scopus)

    Abstract

    An electromagnetic flow sensor was placed on the distal fetal aorta (umbilical flow fraction 78.1±1.6 SEM, %), an inflatable occluder was tied around the umbilical cord, and catheters were placed in distal branches of an umbilical artery and vein, a uterine vein, and in the amniotic cavity. An inflatable occluder was tied around the vagina of some of the ewes. Control values 3 days after surgery were (mean±SE): fetal femoral artery pH, 7.37±0.01; umbilical blood flow, 186±14 ml.min-1.kg fetus-1; fetal arterial blood pressure, 39±3 mmHg; and umbilical venous pressure, 7.4±1.0 mmHg (above intrauterine pressure). Fetal weight at autopsy was 3.1±0.3 kg, n=11. Small increases in umbilical vein pressure caused immediate decreases in placental blood flow without decreases in fetal arterial blood pressure. The relation between venous pressure and umbilical blood flow at constant arterial pressure was that of an inert system, i.e., no evidence of a surrounding pressure (Starling resistor effect or waterfall phenomenon) could be found with increases in venous pressures of 2 to 40 mmHg. The results were not affected by increases in uterine vein pressure between 2 and 30 mmHg, nor by anesthesia and supine position of the ewe, nor by ganglionic blockade of the fetal ANS. It was concluded that surrounding pressures in the fetal placental circulation could not be demonstrated.

    Original languageEnglish (US)
    Title of host publicationAmerican Journal of Physiology
    Pages886-892
    Number of pages7
    Volume230
    Edition4
    StatePublished - 1976

    Fingerprint

    Umbilicus
    Venous Pressure
    Pressure
    Arterial Pressure
    Umbilical Veins
    Fetal Blood
    Veins
    Placental Circulation
    Starlings
    Fetal Weight
    Umbilical Arteries
    Umbilical Cord
    Electromagnetic Phenomena
    Supine Position
    Vagina
    Femoral Artery
    Ambulatory Surgical Procedures
    Aorta
    Autopsy
    Fetus

    ASJC Scopus subject areas

    • Medicine(all)

    Cite this

    Thornburg, K., Bissonnette, J. M., & Faber, J. J. (1976). Absence of fetal placental waterfall phenomenon in chronically prepared fetal lambs. In American Journal of Physiology (4 ed., Vol. 230, pp. 886-892)

    Absence of fetal placental waterfall phenomenon in chronically prepared fetal lambs. / Thornburg, Kent; Bissonnette, J. M.; Faber, J. J.

    American Journal of Physiology. Vol. 230 4. ed. 1976. p. 886-892.

    Research output: Chapter in Book/Report/Conference proceedingChapter

    Thornburg, K, Bissonnette, JM & Faber, JJ 1976, Absence of fetal placental waterfall phenomenon in chronically prepared fetal lambs. in American Journal of Physiology. 4 edn, vol. 230, pp. 886-892.
    Thornburg K, Bissonnette JM, Faber JJ. Absence of fetal placental waterfall phenomenon in chronically prepared fetal lambs. In American Journal of Physiology. 4 ed. Vol. 230. 1976. p. 886-892
    Thornburg, Kent ; Bissonnette, J. M. ; Faber, J. J. / Absence of fetal placental waterfall phenomenon in chronically prepared fetal lambs. American Journal of Physiology. Vol. 230 4. ed. 1976. pp. 886-892
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