Reduced maternal plasma urocortin concentrations and impaired uterine artery blood flow at human mid pregnancy.
OBJECTIVE
Urocortin is a placental neuropeptide belonging to the family of corticotropin-releasing factors (CRFs), playing a role in the uteroplacental blood flow regulation through the binding to specific CRF receptors. Since CRF receptors are expressed in the uterine vascular bed of pregnant rats, and because urocortin has a relaxant effect on uterine vasculature, we evaluated mid-gestation plasma urocortin levels in women with impaired blood flow through uterine arteries.


METHODS
Maternal plasma urocortin was assayed by specific radioimmunoassay and uterine artery resistance index (RI) by Doppler evaluation at 22-24 weeks' gestation in 57 healthy pregnant women, of which 29 showed a monolateral or bilateral uterine artery notch. Statistical analysis was performed by one-way analysis of variance (ANOVA), followed by post-hoc Tukey test for multiple comparison and Pearson correlation coefficient test.


RESULTS
The mean uterine artery RI was significantly (P <.001) higher in women with a notch than healthy controls. Mean +/- SEM maternal plasma urocortin levels were significantly (P <.001) lower in women with unilateral (52.03 +/- 3.25 pg/mL) or bilateral (47.01 +/- 4.16 pg/mL) uterine artery notch than in healthy control pregnant women (84.01 +/- 3.5 pg/mL). While no difference was found in urocortin levels between patients with unilateral or bilateral uterine artery notch, urocortin concentrations inversely correlated with the mean RI (Pearson r = -0.7318; 95% confidence interval -0.8334 to -0.5822; P <.0001).


CONCLUSIONS
The present findings suggest that reduced levels of circulating urocortin are associated with increased uterine artery resistances and support the hypothesis that urocortin may regulate uterine artery tone at mid gestation.
Florio
Pasquale
P
Department of Pediatrics, Obstetrics and Reproductive Medicine, University of Siena, Siena, Italy.
Calonaci
Giulia
G
Severi
Filiberto M
FM
Torricelli
Michela
M
Bocchi
Caterina
C
Fiore
Giovina
G
Linton
Elizabeth A
EA
Petraglia
Felice
F
D000328:Adult; D001158:Arteries / Q000000981:diagnostic imaging; D016022:Case-Control Studies; D003346:Corticotropin-Releasing Hormone / Q000097:blood*; D036861:Delivery, Obstetric; D005260:Female; D005865:Gestational Age; D006801:Humans; D008423:Maternal Age; D011247:Pregnancy; D011262:Pregnancy Trimester, Second; D012016:Reference Values; D018608:Ultrasonography, Doppler; D016216:Ultrasonography, Prenatal; D054832:Urocortins; D014599:Uterus / Q000098:blood supply* / Q000000981:diagnostic imaging
D054832:Urocortins; D003346:Corticotropin-Releasing Hormone