Evidence of interplay between plasma endothelin-1 and 17 beta-estradiol in regulation of uterine blood flow and endometrial growth in infertile women.
OBJECTIVE
To determine the effects of gonadotropin-induced ovarian stimulation on the plasma levels of endothelin-1 as well as on uterine blood flow and endometrial thickness.


METHODS
Controlled cross-over clinical study.


METHODS
Academic research environment.


METHODS
Eighteen volunteer infertile women (31.4 +/- 2.5 years, mean +/- SE) participating in an IVF-ET program.


METHODS
Transvaginal Doppler ultrasound was performed and blood samples were collected 4 days after the LH surge in a spontaneous cycle and 4 days after hCG administration in a subsequent gonadotropin-stimulated cycle.


METHODS
Plasma levels of E2, P, and endothelin-1; uterine artery pulsatility index; and endometrial thickness.


RESULTS
Stimulated cycles were associated with significantly higher E2 levels (101.0 +/- 10.2 versus 723.5 +/- 57.3 pg/mL [conversion Factor to SI unit, 3.671]; spontaneous versus stimulated), thicker endometrium (9.2 +/- 2.5 versus 11.4 +/- 2.9 mm), and lower endothelin-1 levels (2.5 +/- 0.1 versus 2.1 +/- 0.1 pg/mL [conversion factor to SI unit, 0.4]) and pulsatility index (3.22 +/- 0.12 versus 2.63 +/- 0.08) than spontaneous cycles. Endothelin-1 correlated negatively with E2 (r = -0.38), but not with P or pulsatility index. Differences in endothelin-1 and endometrial thickness between spontaneous and stimulated cycles correlated negatively (r = -0.56) with each other.


CONCLUSIONS
Our results suggest an inhibitory role for E2 in the release of endothelin-1, which could be a factor in the regulation of uterine and endometrial blood flow.
Cacciatore
B
B
Department of Obstetrics and Gynecology, Helsinki University Central Hospital, Finland. BRUNO.CACCIATORE@SLP.FIMNET.FI
Simberg
N
N
Tiitinen
A
A
Ylikorkala
O
O
D000328:Adult; D006063:Chorionic Gonadotropin / Q000627:therapeutic use; D018592:Cross-Over Studies; D004624:Embryo Transfer; D004717:Endometrium / Q000473:pathology*; D019332:Endothelin-1 / Q000097:blood*; D004958:Estradiol / Q000097:blood*; D005260:Female; D005307:Fertilization in Vitro; D006801:Humans; D007247:Infertility, Female / Q000473:pathology / Q000503:physiopathology*; D010062:Ovulation Induction; D011673:Pulsatile Flow; D014463:Ultrasonography; D014599:Uterus / Q000098:blood supply* / Q000000981:diagnostic imaging
D006063:Chorionic Gonadotropin; D019332:Endothelin-1; D004958:Estradiol