Antenatal glucocorticoid therapy increases glucose delivery to cerebral circulations during acute hypoxemia in fetal sheep during late gestation.
OBJECTIVE
To determine the effects of 2 maternal injections with dexamethasone on the calculated oxygen and glucose deliveries to fetal cerebral and peripheral circulations during acute hypoxemia in sheep.


METHODS
Beginning at 124 days, ewes received 2 intramuscular injections of either dexamethasone (2 x 12 mg, n = 10) or saline solution (2 x 2 mL, n = 12) 24 hours apart. Hypoxemia (1 hour) was induced 32 hours after the first injection (H1) and 3 days after the second (H2).


RESULTS
In saline solution-treated fetuses, glucose delivery was unchanged or increased in femoral and carotid circulations, respectively, during H1 and H2. In dexamethasone-treated fetuses, the increase in glucose delivery to the head tended to be greater during H1 and was significantly enhanced in dexamethasone- vs saline solution-treated fetuses during H2.


CONCLUSIONS
Two maternal injections with dexamethasone significantly enhanced glucose delivery to the head during acute hypoxemia in the ovine fetus.
Jellyman
Juanita K
JK
Department of Physiology, Development and Neuroscience, University of Cambridge, Cambridge, UK.
Gardner
David S
DS
McGarrigle
Hugh H
HH
Fowden
Abigail L
AL
Giussani
Dino A
DA
D000818:Animals; D001921:Brain / Q000196:embryology; D002339:Carotid Arteries / Q000378:metabolism; D002560:Cerebrovascular Circulation / Q000187:drug effects / Q000502:physiology*; D003907:Dexamethasone / Q000008:administration & dosage* / Q000097:blood; D005260:Female; D005263:Femoral Artery / Q000378:metabolism; D005333:Fetus / Q000378:metabolism*; D005938:Glucocorticoids / Q000008:administration & dosage* / Q000097:blood; D005947:Glucose / Q000378:metabolism*; D006706:Homeostasis / Q000502:physiology; D007273:Injections, Intramuscular; D011247:Pregnancy; D012039:Regional Blood Flow / Q000187:drug effects / Q000502:physiology; D012756:Sheep
D005938:Glucocorticoids; D003907:Dexamethasone; D005947:Glucose