title: Retinoic acid (RA) represses follicle stimulating hormone (FSH)-induced luteinizing hormone (LH) receptor in rat granulosa cells.
abstract: The present study was undertaken to identify the mechanisms underlying the effect of retinoic acid (RA) on the luteinizing hormone receptor (LH-R) in rat granulosa cells. Treatment with FSH produced a substantial increase in LH-R mRNA level, as was expected, while concurrent treatment with increasing concentrations of RA brought about dose-dependent decreases in FSH-induced LH-R mRNA. RA, either alone or in combination with FSH, did not affect intracellular cAMP levels, while it inhibited the effect of 8-Br-cAMP on LH-R mRNA production. Whether the effect of RA and FSH on LH-R mRNA levels was the result of decreased transcription and/or altered mRNA stability was also investigated. The rate of LH receptor mRNA gene transcription, assessed by nuclear run-on transcription assay, was inhibited by the addition of RA. The effect of RA on LH-R mRNA stability was determined by measuring the decay of LH receptor mRNA under conditions known to inhibit transcription. The decay curves for the 5.4-kb LH-R mRNA transcript showed a significant decrease after the addition of RA. It may be possible that RA not only inhibits FSH-induced transcription but also stimulates the production of destabilizing factors for the LH-R mRNA. These findings assist in understanding the molecular mechanism underlying the effect of RA on reproductive function in rat granulosa cells.
authors.affiliation: Department of Obstetrics and Gynecology, School of Medicine, Gunma University, Maebashi, Gunma, 371-8511, Japan. tminegis@sb.gunma-u.ac.jp
authors.forename: T
authors.initials: T
authors.lastname: Minegishi
authors.forename: T
authors.initials: T
authors.lastname: Hirakawa
authors.forename: H
authors.initials: H
authors.lastname: Kishi
authors.forename: K
authors.initials: K
authors.lastname: Abe
authors.forename: Y
authors.initials: Y
authors.lastname: Ibuki
authors.forename: K
authors.initials: K
authors.lastname: Miyamoto
mesh_terms: D000818:Animals; D000242:Cyclic AMP / Q000378:metabolism; D004347:Drug Interactions; D005260:Female; D005640:Follicle Stimulating Hormone / Q000008:administration & dosage / Q000494:pharmacology*; D005786:Gene Expression Regulation / Q000187:drug effects; D006107:Granulosa Cells / Q000187:drug effects* / Q000378:metabolism*; D007700:Kinetics; D020871:RNA Stability / Q000187:drug effects; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D011974:Receptors, LH / Q000187:drug effects* / Q000235:genetics* / Q000378:metabolism; D014212:Tretinoin / Q000008:administration & dosage / Q000494:pharmacology*
chemical_list: D012333:RNA, Messenger; D011974:Receptors, LH; D014212:Tretinoin; D005640:Follicle Stimulating Hormone; D000242:Cyclic AMP