Possible role of uterine contractions in the short-term fluctuations of plasma ACTH concentration in fetal sheep.
Uterine contractions, induced by the administration of oxytocin to sheep between d 123-144 of pregnancy, were associated with a mean transient decrease in fetal PaO2 of 2.8 mm Hg within 5 min. These changes were associated with a rapid increase in the concentration of ACTH in fetal plasma. There was a significant (P less than 0.05) increase in the percentage change (+40 to +47%) over basal ACTH levels in fetal plasma at +5, +15 and +20 min after oxytocin. Administration of saline had no significant effect on intrauterine pressure, fetal PaO2 or fetal plasma ACTH levels. We speculate that increases in uterine activity and/or transient decreases in fetal PaO2 may contribute to short-term fluctuations in plasma ACTH in fetal sheep.
Lye
S J
SJ
Wlodek
M E
ME
Challis
J R
JR
D000324:Adrenocorticotropic Hormone / Q000097:blood*; D000818:Animals; D005260:Female; D005312:Fetal Blood / Q000032:analysis*; D005865:Gestational Age; D010100:Oxygen / Q000378:metabolism; D010121:Oxytocin / Q000494:pharmacology; D011247:Pregnancy; D012756:Sheep; D013997:Time Factors; D014590:Uterine Contraction / Q000187:drug effects
D010121:Oxytocin; D000324:Adrenocorticotropic Hormone; D010100:Oxygen