title: Regulation of ACTH receptor mRNA and binding sites by ACTH and angiotensin II in cultured human and bovine adrenal fasciculata cells.
abstract: Human (HAC) and bovine (BAC) adrenal fasciculata cells express ACTH and angiotensin-II (A-II) receptors. In the present work, we have studied the effects of both hormones on ACTH receptor (ACTH-R) mRNA and binding sites. Both HAC and BAC expressed several ACTH-R transcripts. Although in both cell types, ACTH and A-II increased ACTH-R transcripts in a time- and dose-dependent manner, the maximal effects were different. Thus, ACTH at 10(-9) M enhanced 21- and 5-fold the level of ACTH-R mRNA and binding sites in HAC, whereas in BAC both parameters were enhanced only 3-fold. A-II at 10(-7) M increased 17- and 3.5-fold ACTH-R mRNA and binding sites in HAC, whereas in BAC, it caused only a 2-fold increase in ACTH-R mRNA and a small decrease in receptor number. In HAC, the stimulatory effects of both hormones on ACTH-R mRNA are mainly transcriptional, whereas in BAC they are mainly post-transcriptional, by decreasing the rate of degradation of ACTH-R mRNA. The stimulatory effects of ACTH on ACTH-R in both HAC and BAC were associated with an enhanced steroidogenic response to further hormonal stimulation. In contrast, specific species differences were observed with A-II. Thus, in HAC A-II increased ACTH-R mRNA and binding sites and the ACTH-induced cortisol production, whereas in BAC, A-II caused a slight decrease of ACTH binding sites and steroidogenic desensitization.
authors.affiliation: INSERM/INRA U307, Hôpital Debrousse, Lyon, France.
authors.forename: A
authors.initials: A
authors.lastname: Penhoat
authors.forename: M C
authors.initials: MC
authors.lastname: Lebrethon
authors.forename: M
authors.initials: M
authors.lastname: Bégeot
authors.forename: J M
authors.initials: JM
authors.lastname: Saez
mesh_terms: D000324:Adrenocorticotropic Hormone / Q000494:pharmacology*; D000804:Angiotensin II / Q000494:pharmacology*; D000818:Animals; D001665:Binding Sites; D002417:Cattle; D002478:Cells, Cultured; D006801:Humans; D012333:RNA, Messenger / Q000187:drug effects*; D018043:Receptors, Corticotropin / Q000032:analysis / Q000187:drug effects* / Q000235:genetics; D015383:Zona Fasciculata / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*; D015385:Zona Reticularis / Q000737:chemistry / Q000166:cytology / Q000187:drug effects*
chemical_list: D012333:RNA, Messenger; D018043:Receptors, Corticotropin; D000804:Angiotensin II; D000324:Adrenocorticotropic Hormone