title: Impact of chronic hypoxemia on blood flow to the brain, heart, and adrenal gland in the late-gestation IUGR sheep fetus.
abstract: In the fetus, there is a redistribution of cardiac output in response to acute hypoxemia, to maintain perfusion of key organs, including the brain, heart, and adrenal glands. There may be a similar redistribution of cardiac output in the chronically hypoxemic, intrauterine growth-restricted fetus. Surgical removal of uterine caruncles in nonpregnant ewe results in the restriction of placental growth (PR) and intrauterine growth. Vascular catheters were implanted in seven control and six PR fetal sheep, and blood flow to organs was determined using microspheres. Placental and fetal weight was significantly reduced in the PR group. Despite an increase in the relative brain weight in the PR group, there was no difference in blood flow to the brain between the groups, although PR fetuses had higher blood flow to the temporal lobe. Adrenal blood flow was significantly higher in PR fetuses, and there was a direct relationship between mean gestational PaO2 and blood flow to the adrenal gland. There was no change in blood flow, but a decrease in oxygen and glucose delivery to the heart in the PR fetuses. In another group, there was a decrease in femoral artery blood flow in the PR compared with the Control group, and this may support blood flow changes to the adrenal and temporal lobe. In contrast to the response to acute hypoxemia, these data show that there is a redistribution of blood flow to the adrenals and temporal lobe, but not the heart or whole brain, in chronically hypoxemic PR fetuses in late gestation.
authors.affiliation: Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia.
authors.forename: Rajan
authors.initials: R
authors.lastname: Poudel
authors.affiliation: Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia.
authors.forename: I Caroline
authors.initials: IC
authors.lastname: McMillen
authors.affiliation: Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia.
authors.forename: Stacey L
authors.initials: SL
authors.lastname: Dunn
authors.affiliation: Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia.
authors.forename: Song
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Early Origins of Adult Health Research Group, School of Pharmacy and Medical Sciences, Sansom Institute for Health Research, University of South Australia, Adelaide, South Australia, Australia janna.morrison@unisa.edu.au.
authors.forename: Janna L
authors.identifier: http://orcid.org/0000-0002-8602-8519
authors.initials: JL
authors.lastname: Morrison
mesh_terms: D000311:Adrenal Glands / Q000098:blood supply*; D000818:Animals; D001921:Brain / Q000098:blood supply*; D003331:Coronary Vessels / Q000254:growth & development*; D005260:Female; D005317:Fetal Growth Retardation / Q000097:blood / Q000503:physiopathology*; D005333:Fetus / Q000502:physiology; D005865:Gestational Age; D006321:Heart / Q000503:physiopathology; D000860:Hypoxia / Q000097:blood*; D010920:Placenta / Q000098:blood supply; D011247:Pregnancy; D011297:Prenatal Exposure Delayed Effects; D012756:Sheep
keywords: cortisol; developmental programming; intrauterine growth restriction; placenta; pregnancy