Effects of Umbilical Cord Occlusion in Late Gestation on the Ovine Fetal Brain and Retina

2004 ◽  
Vol 11 (6) ◽  
pp. 369-376 ◽  
Author(s):  
Jhodie R. Duncan ◽  
Emily Camm ◽  
Michelle Loeliger ◽  
Megan L. Cock ◽  
Richard Harding ◽  
...  
Keyword(s):  
Umbilical Cord ◽  
Fetal Brain ◽  
Late Gestation ◽  
Ovine Fetal

Effect of intermittent umbilical cord occlusion on fetal respiratory activity and brain adenosine in late-gestation sheep

2002 ◽  
Vol 14 (1) ◽  
pp. 35 ◽  
Author(s):  
Carole S. Watson ◽  
Rachel Schaefer ◽  
Susan E. White ◽  
Jacobus H. Homan ◽  
Laurence Fraher ◽  
...  
Keyword(s):  
Umbilical Cord ◽  
Fetal Brain ◽  
Extracellular Fluid ◽  
Inhibitory Effect ◽  
Late Gestation ◽  
Fetal Sheep ◽  
Arterial Ph ◽  
Tracheal Pressure ◽  
Ovine Fetal ◽  
Arterial Po2

It was hypothesized that intermittent umbilical cord occlusion (UCO) would inhibit ovine fetal breathing movements (FBM) in association with increased cerebral adenosine levels. To test this hypothesis, on two successive days during late gestation (133–134 days; term = 146 days), microdialysis samples were collected from the brains of 10 chronically instrumented fetal sheep during 2-h periods of complete UCO induced every 30 min (Day 1: 2-min UCOs; Day 2: 4-min UCOs). Control fetuses (n = 10) underwent no UCO. Tracheal pressure was measured throughout. This regimen resulted in a decrease in fetal arterial PO2 (PaO2) during each UCO to 7.3 0.8 mmHg (P<0.01; Day 1) and 8.4 1.1 mmHg (P<0.01; Day 2). Throughout each UCO period, fetal arterial pH (pHa) decreased to 7.28 0.02 (P<0.01; Day 1) and 7.11 0.07 (P<0.01; Day 2). The hourly incidence of FBM decreased significantly only on Day 2, from 38.6 4.1% to 4.1 1.6% (P<0.01). The frequency of deep isolated inspiratory efforts increased from 4.7 2.0 h–1 to 17.6 6.1 h–1 (P<0.05; Day 1) and from 2.2 0.9 h–1 to 33.6 4 h–1 (P<0.01; Day 2). The amplitude of both FBM and deep isolated inspiratory efforts increased during the UCO periods on both days. The concentration of cerebral extracellular fluid (ECF) adenosine during UCO increased by 219 215% (P<0.05; Day 1) and 172 107% (P<0.05; Day 2) over the baseline periods. In conclusion, the severity of the inhibitory effect of repeated UCO on FBM depends, in part, on the length of the occlusions. The inhibition of FBM during intermittent UCO may be mediated by the increase in ECF adenosine in the fetal brain. Furthermore, FBM and deep isolated inspiratory efforts appear to be regulated by different mechanisms.

scholarly journals Genomics of estradiol-3-sulfate action in the ovine fetal hypothalamus

2012 ◽  
Vol 44 (13) ◽  
pp. 669-677 ◽  
Author(s):  
Maria Belen Rabaglino ◽  
Elaine Richards ◽  
Nancy Denslow ◽  
Maureen Keller-Wood ◽  
Charles E. Wood
Keyword(s):  
Feeding Behavior ◽  
Transforming Growth Factor ◽  
Fetal Brain ◽  
Ovis Aries ◽  
Late Gestation ◽  
Postnatal Life ◽  
Growth Factor Signaling ◽  
Fetal Sheep ◽  
Ovine Fetal ◽  
Agouti Related Protein

In fetal sheep during late gestation sulfoconjugated estrogens in plasma reach a concentration 40–100 times greater than unconjugated estrogens. The objective of the present study was to determine the genomics of estradiol-3-sulfate (E2S) action in the ovine fetal brain. The hypothesis was that E2S stimulates genes involved in the neuroendocrine pathways that direct or facilitate fetal development at the end of gestation. Four sets of chronically catheterized ovine twin fetuses were studied (gestational age: 120–127 days gestation) with one infused with E2S intracerebroventricularly (1 mg/day) and the other remaining untreated (control). After euthanasia, mRNA samples were extracted from fetal brains. Only hypothalamic samples were employed for this study given the important function of this brain region in the control of the hypothalamus-pituitary-adrenal axis. Microarray analysis was performed following the Agilent protocol for one-color 8 × 15 microarrays, designed for Ovis aries. A total of 363 known genes were significantly upregulated by the E2S treatment ( P < 0.05). Network and enrichment analyses were performed using the Cytoscape/Bingo software, and the results validated by quantitative real-time PCR. The main overrepresented biological processes resulting from this analysis were feeding behavior, hypoxia response, and transforming growth factor signaling. Notably, the genes involved in the feeding behavior (neuropeptide Y and agouti-related protein) were the most strongly induced by the E2S treatment. In conclusion, E2S may be an important component of the mechanism for activating orexigenic, hypoxia responsiveness and neuroprotective pathways in the lamb as it approaches postnatal life.

PATHOLOGIC CHANGES IN THE PRETERM OVINE FETAL BRAIN FOLLOWING UMBILICAL CORD OCCLUSION

1997 ◽  
Vol 56 (5) ◽  
pp. 599
Author(s):  
M. R. Grafe ◽  
F. Dexter ◽  
R. Goldsmith ◽  
J. Henderson ◽  
J. Reynolds ◽  
...  
Keyword(s):  
Umbilical Cord ◽  
Fetal Brain ◽  
Ovine Fetal

Apoptosis in the preterm and near term ovine fetal brain and the effect of intermittent umbilical cord occlusion

2002 ◽  
Vol 136 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Anna Falkowski ◽  
Rob Hammond ◽  
Victor Han ◽  
Bryan Richardson
Keyword(s):  
Umbilical Cord ◽  
Fetal Brain ◽  
Near Term ◽  
Ovine Fetal

Apoptosis in the Ovine Fetal Brain Following Placental Embolization and Intermittent Umbilical Cord Occlusion

2015 ◽  
Vol 23 (2) ◽  
pp. 249-256 ◽  
Author(s):  
Tuba Aksoy ◽  
Bryan S. Richardson ◽  
Victor K. Han ◽  
Robert Gagnon
Keyword(s):  
Umbilical Cord ◽  
Fetal Brain ◽  
Ovine Fetal

scholarly journals Microtubule-Associated Protein 2 and Synaptophysin in the Preterm and Near-Term Ovine Fetal Brain and the Effect of Intermittent Umbilical Cord Occlusion

2014 ◽  
Vol 22 (3) ◽  
pp. 367-376 ◽  
Author(s):  
Marie J. Czikk ◽  
Stephanie Totten ◽  
Robert Hammond ◽  
Bryan S. Richardson
Keyword(s):  
Umbilical Cord ◽  
Fetal Brain ◽  
Near Term ◽  
Ovine Fetal

scholarly journals Transcriptomics of the late gestation ovine fetal brain: modeling the co-expression of immune marker genes

BMC Genomics ◽  
2014 ◽  
Vol 15 (1) ◽  
pp. 1001 ◽  
Author(s):  
Maria B Rabaglino ◽  
Maureen Keller-Wood ◽  
Charles E Wood
Keyword(s):  
Fetal Brain ◽  
Late Gestation ◽  
Marker Genes ◽  
Immune Marker ◽  
Brain Modeling ◽  
Ovine Fetal

BDNF and TrkB in the Preterm and Near-term Ovine Fetal Brain and the Effect of Intermittent Umbilical Cord Occlusion

2008 ◽  
Vol 15 (9) ◽  
pp. 895-905 ◽  
Author(s):  
Hidekazu Nishigori ◽  
Delfina M. Mazzuca ◽  
Karen L. Nygard ◽  
Victor K. Han ◽  
Bryan S. Richardson
Keyword(s):  
Umbilical Cord ◽  
Fetal Brain ◽  
Near Term ◽  
Ovine Fetal

Effects of in utero endotoxemia on the ovine fetal brain A model for schizophrenia

10.2741/e588 ◽  
2012 ◽  
Vol E4 (8) ◽  
pp. 2745-2753 ◽  
Author(s):  
Boris W Kramer
Keyword(s):  
Fetal Brain ◽  
In Utero ◽  
Ovine Fetal
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