3 beta-Hydroxysteroid dehydrogenase activity and gestagen concentrations in bovine cotyledons and caruncles during gestation and parturition.
3 beta-Hydroxysteroid dehydrogenase (3 beta-HSD) activity in bovine cotyledons was much higher than in caruncles throughout the gestation period. The activity of this enzyme in cotyledons increased greatly to 150.6 +/- 5.8 pmol min-1 mg-1 protein during the seventh month of gestation, reached a peak of 221.0 +/- 34.9 pmol min-1 mg-1 protein during the eighth month, and decreased at parturition. Progesterone and 20 alpha-hydroxyprogesterone concentrations in cotyledons also increased sharply to 2.69 +/- 0.30 and 2.15 +/- 0.42 ng mg-1 protein, respectively, during the seventh month of gestation, reaching peaks of 2.86 +/- 0.47 and 2.51 +/- 0.36 ng mg-1 protein, respectively, during the eighth month and decreasing at parturition, in a manner similar to the activity of 3 beta-hydroxysteroid dehydrogenase. The fluctuation of 17 alpha-hydroxyprogesterone concentration in cotyledons was different from that of progesterone and 20 alpha-hydroxyprogesterone. These findings indicate that the activity of 3 beta-hydroxysteroid dehydrogenase in the placenta is enhanced during the third trimester, and progesterone synthesized in the cotyledons is converted concurrently to 20 alpha-hydroxyprogesterone before progesterone is transferred to the fetal blood.
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
D019326:17-alpha-Hydroxyprogesterone; D004092:20-alpha-Dihydroprogesterone / Q000378:metabolism; D015096:3-Hydroxysteroid Dehydrogenases / Q000378:metabolism*; D000650:Amnion / Q000201:enzymology*; D000818:Animals; D002417:Cattle / Q000378:metabolism*; D005260:Female; D006908:Hydroxyprogesterones / Q000378:metabolism; D007743:Labor, Obstetric / Q000378:metabolism*; D010920:Placenta / Q000201:enzymology*; D011247:Pregnancy; D011270:Pregnancy, Animal / Q000378:metabolism*; D011374:Progesterone / Q000378:metabolism*
D006908:Hydroxyprogesterones; D004092:20-alpha-Dihydroprogesterone; D011374:Progesterone; D019326:17-alpha-Hydroxyprogesterone; D015096:3-Hydroxysteroid Dehydrogenases