Up-regulation of oxytocin receptor expression at term is related to maternal body mass index.
BACKGROUND
The likelihood of cesarean is in part related to maternal body mass index (BMI). Myometrial changes may be responsible.


METHODS
Myometrial biopsies were collected from the upper edge of the hysterotomy from women undergoing scheduled cesarean with term, singleton gestations. Oxytocin receptor and connexin-43 mRNA protein expression was quantified with real-time polymerase chain reaction and Western blot.


RESULTS
Twenty subjects were recruited: 13 repeat and 7 primary cesareans. Oxytocin receptor mRNA was associated with BMI among women undergoing primary (r = 0.75; p = 0.05) but not repeat cesarean (p > 0.05). Controlling for gestational age, this association strengthened (p = 0.004). Receptor protein expression showed a linear correlation with BMI in the primary cesarean group (p = 0.002). Connexin-43 mRNA expression was not related to BMI in women undergoing primary (r = -0.14, p = 0.76) or repeat (r = -0.01, p = 0.86) cesarean.


CONCLUSIONS
Oxytocin receptor, but not connexin-43, expression is related to BMI, suggesting an alteration in oxytocin receptor expression or function related to obesity.
Department of Obstetrics and Gynecology, University of Kentucky, Lexington, KY, USA. Matthew.Garabedian@hhs.sccgov.org
Matthew J
MJ
Garabedian
Wendy F
WF
Hansen
Lauren A
LA
McCord
Mark A
MA
Manning
John M
JM
O'Brien
Thomas E
TE
Curry
D000328:Adult; D015153:Blotting, Western; D015992:Body Mass Index; D002585:Cesarean Section; D018031:Connexin 43 / Q000378:metabolism; D005260:Female; D006801:Humans; D028322:Inhibin-beta Subunits / Q000378:metabolism; D009215:Myometrium / Q000378:metabolism; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism; D018045:Receptors, Oxytocin / Q000378:metabolism*; D020133:Reverse Transcriptase Polymerase Chain Reaction; D015854:Up-Regulation / Q000502:physiology*
D018031:Connexin 43; D012333:RNA, Messenger; D018045:Receptors, Oxytocin; D028322:Inhibin-beta Subunits