{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,4]],"date-time":"2026-05-04T18:37:17Z","timestamp":1777919837303,"version":"3.51.4"},"reference-count":0,"publisher":"S. Karger AG","license":[{"start":{"date-parts":[[2008,4,1]],"date-time":"2008-04-01T00:00:00Z","timestamp":1207008000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/karger.com\/pages\/terms-and-conditions"},{"start":{"date-parts":[[2008,4,1]],"date-time":"2008-04-01T00:00:00Z","timestamp":1207008000000},"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":"Long-term 17\u03b2-estradiol (E<sub>2<\/sub>) treatment in rats decreases tuberoinfundibular dopaminergic (TIDA) neuronal function. The objective of this study was to determine if the decline in TIDA function after E<sub>2<\/sub> treatment in Fischer 344 (F344) rats is sustained long after removal of E<sub>2<\/sub>. Ovariectomized (OVX) F344 rats were each implanted with an E<sub>2<\/sub>-containing or empty Silastic capsule for 4 weeks; the capsule was then removed, and 26 weeks later acute experiments were performed. Release of 3H from median eminence tissue in vitro in response to electrical stimulation after 3H-DA accumulation was not different between E<sub>2<\/sub>-treated rats and OVX controls, even though serum prolactin (PRL) was 4-fold greater in E<sub>2<\/sub>-treated animals. Acute administration of apomorphine hydrochloride, a DA receptor agonist, at 2 doses, reduced serum PRL values as much in E<sub>2<\/sub>-treated animals as in OVX control rats. Injection of morphine sulfate or nomifensine maleate, which directly influence TIDA neurons, resulted in nonsignificant serum PRL responses in animals long after E<sub>2<\/sub> withdrawal as compared to the greater response in OVX control rats. To further evaluate TIDA neuronal function, OVX non-E<sub>2<\/sub>-treated rats and animals 26 weeks after E<sub>2<\/sub> withdrawal received a 3-day E<sub>2<\/sub> challenge which increased the stimulation-evoked release of 3H from the median eminence tissue in vitro 2-fold in OVX control rats but had no effect in rats given E<sub>2<\/sub> 26 weeks previously. The difference in the stimulation-evoked release occurred in the presence of similar circulating serum PRL levels in the two groups as a result of the 3-day E<sub>2<\/sub> treatment. These data indicate that TIDA neurons exhibit a decreased responsiveness to most stimuli after long-term withdrawal from chronic E<sub>2<\/sub> treatment, even though the E<sub>2<\/sub>-treated anterior pituitary was fully responsive to the dopaminergic agonist, apomorphine. Thus, E<sub>2<\/sub> administration to OVX F344 rats for 4 weeks appears to result in a permanent decline in TIDA neuronal function. The mechanism(s) responsible for this permanent effect of E<sub>2<\/sub> is not known at present.<\/jats:p>","DOI":"10.1159\/000124647","type":"journal-article","created":{"date-parts":[[2008,4,2]],"date-time":"2008-04-02T11:56:21Z","timestamp":1207137381000},"page":"211-216","source":"Crossref","is-referenced-by-count":10,"title":["Evidence for a Permanent Decline in Tuberoinfundibular Dopaminergic Neuronal Function after Chronic Estrogen Treatment Is Terminated in Fischer 344 Rats"],"prefix":"10.1159","author":[{"given":"Paul E.","family":"Gottschall","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Joseph","family":"Meites","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"127","published-online":{"date-parts":[[2008,4,1]]},"container-title":["Neuroendocrinology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.karger.com\/Article\/Pdf\/124647","content-type":"application\/pdf","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/karger.com\/article-pdf\/doi\/10.1159\/000124647","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,5,1]],"date-time":"2026-05-01T19:13:17Z","timestamp":1777662797000},"score":1,"resource":{"primary":{"URL":"https:\/\/karger.com\/article\/doi\/10.1159\/000124647"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2008,4,1]]},"references-count":0,"URL":"https:\/\/doi.org\/10.1159\/000124647","archive":["Portico"],"relation":{},"ISSN":["0028-3835","1423-0194"],"issn-type":[{"value":"0028-3835","type":"print"},{"value":"1423-0194","type":"electronic"}],"subject":[],"published":{"date-parts":[[2008,4,1]]}}}