{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,20]],"date-time":"2026-09-20T12:18:42Z","timestamp":1789906722582,"version":"4.0.1"},"reference-count":0,"publisher":"S. Karger AG","license":[{"start":{"date-parts":[[2008,4,7]],"date-time":"2008-04-07T00:00:00Z","timestamp":1207526400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"},{"start":{"date-parts":[[2008,4,7]],"date-time":"2008-04-07T00:00:00Z","timestamp":1207526400000},"content-version":"tdm","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Neuroendocrinology"],"abstract":"Previous studies have shown that the hypothalamic concentrations of \u03b2-endorphin (\u03b2-EP) and other proopiomelanocortin (POMC)-derived peptides change in the female rat following castration and gonadal steroid replacement. In this study we have measured POMC mRNA by solution hybridization assay in the medial basal hypothalamus (MBH) of ovariectomized rats treated with a regimen of estradiol (E<sub>2<\/sub>) that we have previously shown alters brain \u03b2-EP peptide content. In addition the effect of progesterone (P) was also studied. In the first experiment the concentration of \u03b2-EP and \u03b1-melanocyte-stimulating hormone (\u03b1-MSH) in the MBH of castrated rats decreased significantly after 3 weeks of E<sub>2<\/sub> treatment compared to castrated unreplaced rats: \u03b2-EP decreased from 6.00 \u00b1 0.46 to 4.32 \u00b1 0.38 ng\/mg protein and \u03b1-MSH decreased from 3.00 \u00b1 0.23 to 2.35 \u00b1 0.15 ng\/mg protein (p < 0.05). A similar decrease in peptide content was noted in the anterior hypothalamus\/ preoptic area. A parallel reduction in the concentration of POMC mRNA was measured in the MBH of the E<sub>2<\/sub>-replaced animals: 1.17 \u00b1 0.14 vs. 0.72 \u00b1 0.08 pg\/\u00b5g RNA (p < 0.02). In a second study castrated rats were studied after 2 weeks of E<sub>2<\/sub> or E<sub>2<\/sub> plus P treatment. After 2 weeks, POMC peptide levels did not change significantly in the MBH of either the E<sub>2<\/sub>- or E<sub>2<\/sub> plus P-treated rats. POMC mRNA, however, was significantly reduced from 1.10 \u00b1 0.10 pg\/\u00b5g RNA in the unreplaced rats to 0.58 \u00b1 0.05 and 0.61 \u00b1 0.06 pg\/\u00b5g RNA after E<sub>2<\/sub> or E<sub>2<\/sub> plus P, respectively (p < 0.001). No significant change in the concentration of \u03b2-EP or POMC mRNA was noted after 48 h of E<sub>2<\/sub>. We conclude that E<sub>2<\/sub> has significant effects on POMC gene expression and peptide levels in the MBH of female rats. The parallel decrease in POMC mRNA and peptide levels and the fact that the changes in gene expression precede the changes in peptide content are consistent with an inhibitory effect of E<sub>2<\/sub> on the biosynthesis of POMC in the MBH under these conditions.<\/jats:p>","DOI":"10.1159\/000126111","type":"journal-article","created":{"date-parts":[[2008,4,7]],"date-time":"2008-04-07T07:33:24Z","timestamp":1207553604000},"page":"167-173","source":"Crossref","is-referenced-by-count":36,"title":["Estradiol Regulation of Proopiomelanocortin Gene Expression and Peptide Content in the Hypothalamus"],"prefix":"10.1159","author":[{"given":"Susan L","family":"Treiser","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sharon L","family":"Wardlaw","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"127","published-online":{"date-parts":[[2008,4,7]]},"container-title":["Neuroendocrinology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/126111","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/karger.com\/article-pdf\/doi\/10.1159\/000126111","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T19:30:59Z","timestamp":1777663859000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000126111"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,4,7]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1159\/000126111","archive":["Portico"],"relation":{},"ISSN":["0028-3835","1423-0194"],"issn-type":[{"value":"0028-3835","type":"print"},{"value":"1423-0194","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,4,7]]}}}