Regulation of low density lipoprotein receptor mRNA levels by estradiol 17beta and chorionic gonadotropin in human placenta.
Inhibition of synthesis of estradiol 17beta by the addition of inhibitors of aromatase, a key enzyme in the biosynthesis of estradiol 17beta, or addition of tamoxifen - an estrogen receptor antagonist, to human placental minces resulted in an increase in the level of LDL-receptor mRNA. This increase could be blocked by the simultaneous addition of estradiol 17beta. A concentration dependent effect of estradiol 17beta on the level of LDL-receptor mRNA was seen both in first trimester, and term placenta. Addition of human chorionic gonadotropin (hCG) to term placental minces also increased the LDL-receptor mRNA levels. When hCG and cycloheximide were added together, an additive effect was observed. The results obtained in this study suggest that the LDL-receptor mRNA levels in the human placenta are regulated by estradiol 17beta and hCG.
Shanker
Y G
YG
Department of Biochemistry, Indian Institute of Science, Bangalore.
Shetty
U P
UP
Rao
A J
AJ
D000616:Aminoglutethimide / Q000494:pharmacology; D000733:Androstatrienes / Q000494:pharmacology; D047072:Aromatase Inhibitors; D015152:Blotting, Northern; D002784:Cholesterol / Q000494:pharmacology; D006063:Chorionic Gonadotropin / Q000494:pharmacology*; D003513:Cycloheximide / Q000494:pharmacology; D004958:Estradiol / Q000378:metabolism / Q000494:pharmacology / Q000502:physiology*; D004965:Estrogen Antagonists / Q000494:pharmacology*; D005260:Female; D018507:Gene Expression Regulation, Developmental; D006801:Humans; D066298:In Vitro Techniques; D010920:Placenta / Q000378:metabolism*; D010929:Placentation; D011247:Pregnancy; D011261:Pregnancy Trimester, First; D011374:Progesterone / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D011973:Receptors, LDL / Q000235:genetics*; D013629:Tamoxifen / Q000494:pharmacology
C115984:1,4,6-androstatrien-3,17-dione; D000733:Androstatrienes; D047072:Aromatase Inhibitors; D006063:Chorionic Gonadotropin; D004965:Estrogen Antagonists; D012333:RNA, Messenger; D011973:Receptors, LDL; D013629:Tamoxifen; D000616:Aminoglutethimide; D011374:Progesterone; D004958:Estradiol; D002784:Cholesterol; D003513:Cycloheximide