Aromatase activity and oestrogen concentrations in bovine cotyledons and caruncles during gestation and parturition.
Two peaks of aromatase activities were detected in bovine cotyledons, 2.76 +/- 0.96 pmol min-1 mg-1 protein at month five of gestation and 3.62 +/- 0.78 pmol min-1 mg-1 protein immediately after parturition, but aromatase activity in caruncles was very low throughout gestation. Oestrone concentrations in the cotyledons and caruncles were 0.93 +/- 0.50 and 1.51 +/- 0.69 ng mg-1 protein at month five of gestation, but 4.31 +/- 1.66 and 3.36 +/- 0.98 ng mg-1 protein immediately after parturition, indicating a biphasic pattern. Our findings suggest that oestrogen synthesis in the bovine placenta increased to a maximum at least twice during the period from gestation to parturition; at month five of gestation and at parturition the changes in aromatase activity may only be partially explained by changes in oestrogen production.
Tsumagari
S
S
Department of Veterinary Obstetrics and Gynecology, Nihon University, Kanagawa, Japan.
Kamata
J
J
Takagi
K
K
Tanemura
K
K
Yosai
A
A
Takeishi
M
M
D000818:Animals; D001141:Aromatase / Q000378:metabolism*; D002417:Cattle / Q000378:metabolism*; D004958:Estradiol / Q000378:metabolism; D004967:Estrogens / Q000378:metabolism*; D004970:Estrone / Q000378:metabolism; D005260:Female; D005865:Gestational Age; D007743:Labor, Obstetric / Q000378:metabolism; D008297:Male; D010920:Placenta / Q000378:metabolism*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*
D004967:Estrogens; D004970:Estrone; D004958:Estradiol; D001141:Aromatase