The effects of hypoxia and hyperoxia on fetal-placental vascular tone and inflammatory cytokine production.
OBJECTIVE
To determine the effects of fetal hypoxia and hyperoxia on placental vascular tone and production of interleukin-6 and tumor necrosis factor-alpha.


METHODS
The maternal and fetal circulation of 2 cotyledons from 5 human placentas were perfused for 4 hours. The fetal circulation of 1 cotyledon was perfused with hypoxic Hanks' balanced salt solution; the other was perfused with hyperoxic Hanks' balanced salt solution. Fetal vascular pressures were recorded every 10 minutes, and fetal vein effluents were collected hourly.


RESULTS
Fetal-placental vascular perfusion pressure was reduced from baseline during hypoxic conditions. Cytokine concentrations were elevated during hyperoxic conditions compared with hypoxic conditions, with significant differences achieved at 2, 3, and 4 hours for interleukin-6 and at 4 hours for tumor necrosis factor-alpha.


CONCLUSIONS
Fetal-placental vasodilation may be a compensatory mechanism to improve hypoxic conditions. Supraphysiologic oxygenation may contribute to the fetal inflammatory response syndrome and to the development of cerebral palsy.
Pierce
B T
BT
Division of Maternal-Fetal Medicine, Madigan Army Medical Center, Fort Lewis, Wash, USA.
Napolitano
P G
PG
Pierce
L M
LM
Apodaca
C C
CC
Hume
R F
RF
Calhoun
B C
BC
D005315:Fetal Diseases / Q000503:physiopathology*; D005333:Fetus / Q000098:blood supply*; D006801:Humans; D018496:Hyperoxia / Q000503:physiopathology*; D000860:Hypoxia / Q000503:physiopathology*; D018836:Inflammation Mediators / Q000378:metabolism*; D015850:Interleukin-6 / Q000378:metabolism; D010920:Placenta / Q000098:blood supply*; D014409:Tumor Necrosis Factor-alpha / Q000378:metabolism; D014666:Vasomotor System / Q000503:physiopathology*
D018836:Inflammation Mediators; D015850:Interleukin-6; D014409:Tumor Necrosis Factor-alpha