{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T18:53:39Z","timestamp":1777920819496,"version":"3.51.4"},"reference-count":0,"publisher":"S. Karger AG","license":[{"start":{"date-parts":[[2008,4,8]],"date-time":"2008-04-08T00:00:00Z","timestamp":1207612800000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"},{"start":{"date-parts":[[2008,4,8]],"date-time":"2008-04-08T00:00:00Z","timestamp":1207612800000},"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":"<jats:p>In experiment I we studied the capacity of progesterone (P) and two nonsteroidal agents that activate lordosis, but do not bind to the progestin receptor (PR), i.e. luteinizing hormone-releasing hormone (LHRH) and prostaglandin E&lt;sub&gt;2&lt;\/sub&gt; (PGE&lt;sub&gt;2&lt;\/sub&gt;) to induce sequential inhibition (SI) in ovariectomized estradiol-primed rats. The administration of 1 mg P, 5 \u00b5g LHRH or 100 \u00b5g PGE&lt;sub&gt;2&lt;\/sub&gt; induced significant lordosis within 4 h. An injection of 1 mg P, 24 h after the administration of the above lordogenic agents, induced significant lordosis in rats pretreated with LHRH or PGE&lt;sub&gt;2&lt;\/sub&gt;, but not in those pretreated with P. Thus, only P induced SI (p &lt; 0.025). In experiment II we investigated if progestin-induced SI results in a reduced capacity of the subjects to respond only to P or to other lordogenic agents. The synthetic progestin norgestrel (400 \u00b5g administered 24 h earlier) significantly reduced the responsiveness to P (p &lt; 0.01), LHRH (p &lt; 0.01), PGE&lt;sub&gt;2&lt;\/sub&gt; (p &lt; 0.025) and dibutyryl cyclic AMP (db cAMP p &lt; 0.01). Results suggest that SI is triggered only by agents that bind to the PR (experiment I) and that it decreases the responsiveness of rats not only to P but also to other lordogenic agents (experiment II).<\/jats:p>","DOI":"10.1159\/000126457","type":"journal-article","created":{"date-parts":[[2008,4,8]],"date-time":"2008-04-08T06:52:44Z","timestamp":1207637564000},"page":"940-945","source":"Crossref","is-referenced-by-count":25,"title":["Progesterone, but Not LHRH or Prostaglandin E\n                    <sub>2<\/sub>\n                    , Induces Sequential Inhibition of Lordosis to Various Lordogenic Agents"],"prefix":"10.1159","author":[{"given":"Gabriela","family":"Gonz\u00e1lez-Mariscal","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Angel I.","family":"Melo","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Carlos","family":"Beyer","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2008,4,8]]},"container-title":["Neuroendocrinology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/126457","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/karger.com\/article-pdf\/doi\/10.1159\/000126457","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T19:36:22Z","timestamp":1777664182000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000126457"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,4,8]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1159\/000126457","archive":["Portico"],"relation":{},"ISSN":["0028-3835","1423-0194"],"issn-type":[{"value":"0028-3835","type":"print"},{"value":"1423-0194","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,4,8]]}}}