Hormonal regulation of luteinizing hormone/chorionic gonadotropin receptor mRNA in rat ovarian cells during follicular development and luteinization.
To determine whether hormone-dependent changes in the levels of LH/CG receptor in the rat ovary are associated with changes in expression of LH/CG receptor mRNAs, total RNA from rat follicles and corpora lutea at various stages of development was prepared and analyzed by Northern blots and/or solution hybridization. Whereas small antral follicles contained lo amounts of LH/CG receptor mRNAs, the growth of preovulatory (PO) follicles was associated with an increase in all LH/CG receptor mRNA transcripts. Induction of LH/CG receptor mRNAs in granulosa cells of hypophysectomized rats was dependent on the synergistic effects of estradiol and FSH. An LH/CG surge in vivo or LH treatment of PO follicles in vitro caused a rapid decline of all LH/CG receptor mRNAs in PO follicles, which was prevented by cycloheximide. Newly formed corpora lutea (days 1-4 postovulation) contained low amounts of LH/CG receptor mRNAs unless the rats were pregnant or treated exogenously with PRL. During pregnancy, corpora lutea isolated on days 4-19 of gestation contained high levels of LH/CG receptor mRNAs, which decreased markedly on days 21 and 24, the time of functional luteolysis and decreasing LH/CG receptor levels. These studies demonstrate that hormonal regulation of LH/CG receptor mRNA in rat ovarian cells parallels changes in LH/CG receptor levels and involves diverse molecular mechanisms, including 1) low concentrations of cAMP (elicited by FSH) in developing follicles, 2) inhibition by high concentrations of cAMP (elicited by LH/CG) in PO follicles, and 3) induction and maintenance by PRL in corpora lutea of gestation.
Segaloff
D L
DL
Population Council, New York, New York 10021.
Wang
H Y
HY
Richards
J S
JS
D000818:Animals; D006063:Chorionic Gonadotropin / Q000378:metabolism; D003338:Corpus Luteum / Q000378:metabolism*; D004958:Estradiol / Q000494:pharmacology; D005260:Female; D005640:Follicle Stimulating Hormone / Q000494:pharmacology; D005786:Gene Expression Regulation / Q000187:drug effects*; D006107:Granulosa Cells / Q000378:metabolism; D006728:Hormones / Q000494:pharmacology*; D007016:Hypophysectomy; D007986:Luteinizing Hormone / Q000378:metabolism / Q000494:pharmacology; D009693:Nucleic Acid Hybridization; D006080:Ovarian Follicle / Q000254:growth & development*; D010053:Ovary / Q000254:growth & development / Q000378:metabolism*; D010060:Ovulation / Q000502:physiology; D011247:Pregnancy; D012333:RNA, Messenger / Q000378:metabolism*; D051381:Rats; D011974:Receptors, LH / Q000235:genetics* / Q000378:metabolism; D013799:Theca Cells / Q000378:metabolism
D006063:Chorionic Gonadotropin; D006728:Hormones; D012333:RNA, Messenger; D011974:Receptors, LH; D004958:Estradiol; D007986:Luteinizing Hormone; D005640:Follicle Stimulating Hormone