PMID- 8943772 OWN - NLM STAT- MEDLINE DCOM- 19961223 LR - 20190709 IS - 0022-0795 (Print) IS - 0022-0795 (Linking) VI - 151 IP - 1 DP - 1996 Oct TI - Evidence of thyrotropin-releasing hormone (TRH) gene expression in rat anterior pituitaries and modulation by estrogens of TRH-like immunoreactivity and TRH-elongated peptide contents. PG - 87-96 AB - TRH gene expression in the anterior pituitary has previously been reported in the human in vivo and in the rat in vitro. Until now, modulation of this synthesis with glucocorticoids and thyroid hormones has been observed in rats. The present study demonstrates for the first time that the TRH gene is also expressed, in vivo, in the rat anterior pituitary and that anterior pituitary TRH-like immunoreactivity (TRH-LI) and elongated forms of the immediate TRH progenitor sequence (TRH-elongated peptide) contents are also modulated by estrogens (E2). To investigate the presence of proTRH mRNA in the rat anterior pituitary, total RNA was reverse transcribed (RT) and the RT products were then amplified by PCR. Treatments with E2 were performed on intact and ovariectomized (OVX) rats for 2 months. TRH-LI was measured by RIA with an antibody which did not recognize the TRH-like peptide. pGlu-Glu-Pro-NH2 (< EEP-NH2) (cross-reactivity < 0.1%) and was characterized further as TRH-LI by HPLC. TRH-elongated peptides were measured by EIA and characterized by Sephadex G-50 chromatography and immunoblotting (molecular mass 25-35 kDa). The plasma prolactin levels and the pituitary sizes were increased by E2 treatment in both intact and OVX rats. Anterior pituitary TRH-LI increased in intact E2-treated rats compared with intact rats (82.7 +/- 19.0 versus 39.6 +/- 3.6 fmol/mg protein; means +/- S.E.M.; P < 0.001). This increase was greater when E2 was administered to OVX rats (599.0 +/- 98.4 after E2 treatment versus 58.6 +/- 3.6 fmol/mg protein: P < 0.001). In intact rats, anterior pituitary TRH-elongated peptide contents were not modified by E2 treatment while they were significantly decreased in OVX E2-treated rats (144.6 +/- 8.8 versus 223.7 +/- 9.5 fmol/mg protein; P < 0.001). These results demonstrate TRH gene expression in the rat anterior pituitary in vivo and suggest that E2 treatment is responsible for an increase in anterior pituitary TRH-LI, together with a decrease in TRH-elongated peptide contents. FAU - Croissandeau, G AU - Croissandeau G AD - Unite INSERM 223, Faculte de Medecine Pitie-Salpetriere, Paris, France. FAU - Schussler, N AU - Schussler N FAU - Grouselle, D AU - Grouselle D FAU - Pagesy, P AU - Pagesy P FAU - Rauch, C AU - Rauch C FAU - Bayet, M C AU - Bayet MC FAU - Peillon, F AU - Peillon F FAU - Le Dafniet, M AU - Le Dafniet M LA - eng PT - Journal Article PL - England TA - J Endocrinol JT - The Journal of endocrinology JID - 0375363 RN - 0 (Protein Precursors) RN - 0 (RNA, Messenger) RN - 4TI98Z838E (Estradiol) RN - 5Y5F15120W (Thyrotropin-Releasing Hormone) RN - 9002-62-4 (Prolactin) RN - 98616-54-7 (pro-thyrotropin releasing hormone) RN - SZB83O1W42 (Pyrrolidonecarboxylic Acid) SB - IM MH - Animals MH - Chromatography, High Pressure Liquid MH - Estradiol/*pharmacology MH - Female MH - Gene Expression MH - Organ Size/drug effects MH - Ovariectomy MH - Pituitary Gland, Anterior/drug effects/*metabolism MH - Prolactin/blood MH - Protein Precursors/genetics/metabolism MH - Pyrrolidonecarboxylic Acid/analogs & derivatives MH - RNA, Messenger/analysis MH - Radioimmunoassay MH - Rats MH - Rats, Wistar MH - Thyrotropin-Releasing Hormone/*genetics/metabolism EDAT- 1996/10/01 00:00 MHDA- 1996/10/01 00:01 CRDT- 1996/10/01 00:00 PHST- 1996/10/01 00:00 [pubmed] PHST- 1996/10/01 00:01 [medline] PHST- 1996/10/01 00:00 [entrez] AID - 10.1677/joe.0.1510087 [doi] PST - ppublish SO - J Endocrinol. 1996 Oct;151(1):87-96. doi: 10.1677/joe.0.1510087.