Prostaglandin control of the renal circulation in response to hypoxemia in the fetal lamb in utero.
Open Access
- 1 August 1979
- journal article
- research article
- Published by Wolters Kluwer Health in Circulation Research
- Vol. 45 (2) , 172-179
- https://doi.org/10.1161/01.res.45.2.172
Abstract
We studied the effects of 10-minute periods of hypoxemia in unanesthetized fetal lambs in utero instrumented for measurements of arterial pressure and renal and iliac blood flows. Fetal hypoxemia, induced by delivering a hypoxic gas mixture to the ewe, was characterized by a reduction in fetal PaO2 from 20.1 +/- 1.4 to 8.8 +/- 1.0 mm Hg (mean +/- SE). The fetus responded with bradycardia and persistent vasoconstriction in the iliac bed throughout the 10-minute period. In contrast, renal resistance rose significantly only at the end of the hypoxemic period. After 5-7 minutes of hypoxemia, when iliac flow had fallen by 40 +/- 4% and iliac resistance had risen by 86 +/- 13%, renal flow and resistance were not changed significantly from control; in fact, we found that renal flow rose substantially at this time in several fetal lambs. After blockade of prostaglandin synthesis with either indomethacin or meclofenamate, renal flow fell after 5-7 minutes of hypoxemia by 36 +/- 5%. The reduction in renal flow and increases in renal resistance were significantly greater than was observed prior to blockade of prostaglandin synthesis. Thus, fetal hypoxemia elicits bradycardia and intense peripheral vasoconstriction reflected by the changes in the iliac bed, with relative sparing of the reanl bed. The relative protection of the renal bed during fetal hypoxemia appears to be related to a mechanism involving prostaglandins, since after blockade of prostaglandin synthesis, hypoxemia results in intense renal vasoconstriction.This publication has 12 references indexed in Scilit:
- Closure of the Ductus Arteriosus in Premature Infants by Inhibition of Prostaglandin SynthesisNew England Journal of Medicine, 1976
- Pharmacologic Closure of Patent Ductus Arteriosus in the Premature InfantNew England Journal of Medicine, 1976
- Prostaglandins in the circulation of the fetal lambProstaglandins, 1976
- Prostaglandin control of renal circulation in the unanesthetized dog and baboonAmerican Journal of Physiology-Legacy Content, 1975
- Effects of Indomethacin on Local Blood Flow Regulation in Canine Heart and KidneyExperimental Biology and Medicine, 1975
- Cardiovascular responses to hypoxemia and acidemia in fetal lambsAmerican Journal of Obstetrics and Gynecology, 1974
- Effects of Hemorrhage on Regional Blood Flow Distribution in Dogs and PrimatesJournal of Clinical Investigation, 1974
- Contribution of Intrarenal Generation of Prostaglandin to Autoregulation of Renal Blood Flow in the DogCirculation Research, 1973
- Differential Efect of Noradrenaline and Renal Nerve Stimulation on Vascular Resistance in the Dog Kidney and the Release of a Prostaglandin E-Like SubstanceClinical Science, 1972
- Release of prostaglandin-like material from dog kidney during nerve stimulationAmerican Journal of Physiology-Legacy Content, 1970