Secretion of progesterone, estradiol-17beta, PGE, PGF2alpha, and pregnancy-specific protein B by 90-day intact and ovariectomized pregnant ewes.
Ninety-day pregnant ewes were either laparotomized, ovaries left in situ or bilaterally ovariectomized, and a jugular venous catheter and an inferior vena cava catheter via the saphenous vein were installed. Seven days later, placenta slices were collected and incubated in vitro for 4 h. Secretions of progesterone, PGE, estradiol-17beta and pregnancy-specific protein B (PSPB) in vitro by placenta from ovariectomized ewes were increased (P < or = 0.05) by 2.7-, 3.6-, 2.2-, and 2.4-fold, respectively, when compared to placenta slices from intact 90-day pregnant ewes. Secretion of PGF2alpha in vitro was unchanged (P > or = 0.05). Ovariectomy decreased (P < or = 0.05) jugular venous progesterone for 78 h followed by a quadratic increase (P < or = 0.05), whereas progesterone remained unchanged (P > or = 0.05) in intact ewes over the 162-h sampling period. Ovariectomy increased (P < or = 0.05) PGE in inferior vena cava plasma over the last half of the 162-h sampling period, whereas concentration of PGF2alpha did not change (P > or = 0.05). Increases in PGE occurred before the increase in progesterone. Concentrations of PSPB in inferior vena cava plasma of ovariectomized pregnant ewes increased (P < or = 0.05) during the last half of the 162-h sampling period, but not in intact ewes (P > or = 0.05). PSPB increased before PGE and progesterone. Concentrations of estradiol-17beta in jugular venous plasma of ovariectomized pregnant ewes increased (P < or = 0.05) during the last half of the sampling period, but not in intact ewes (P > or = 0.05). Increases in estradiol-17beta occurred before increases in PSPB. It is concluded that these data support the hypothesis that estradiol-17beta may control placental secretion of PSPB; PSPB may regulate placental secretion of PGE; and PGE may regulate placental secretion of progesterone.
Weems
Y S
YS
Department of Animal Science, University of Hawaii, Honolulu 96822, USA.
Bridges
P J
PJ
LeaMaster
B R
BR
Sasser
R G
RG
Vincent
D L
DL
Weems
C W
CW
D000818:Animals; D016282:Aspartic Acid Endopeptidases / Q000097:blood*; D015237:Dinoprost / Q000097:blood*; D004958:Estradiol / Q000097:blood*; D005260:Female; D007813:Laparotomy; D010052:Ovariectomy; D010920:Placenta / Q000378:metabolism; D011247:Pregnancy; D011257:Pregnancy Proteins / Q000097:blood*; D011270:Pregnancy, Animal / Q000097:blood / Q000502:physiology*; D011374:Progesterone / Q000097:blood*; D011458:Prostaglandins E / Q000097:blood*; D012756:Sheep / Q000097:blood / Q000502:physiology*; D013997:Time Factors
D011257:Pregnancy Proteins; D011458:Prostaglandins E; D011374:Progesterone; D004958:Estradiol; D015237:Dinoprost; D016282:Aspartic Acid Endopeptidases; C094766:pregnancy-associated glycoprotein 1