{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,27]],"date-time":"2026-10-27T22:41:28Z","timestamp":1793140888343,"version":"4.5.0"},"reference-count":0,"publisher":"National Academy of Sciences","issue":"24","content-domain":{"domain":["www.pnas.org"],"crossmark-restriction":true},"short-container-title":["Proc. Natl. Acad. Sci. U.S.A."],"published-print":{"date-parts":[[1992,12,15]]},"abstract":"<jats:p>Previous work showed that production of transforming growth factor beta (TGF-beta) by osteoblast-like rat UMR 106 cells was increased by 17 beta-estradiol at physiological concentrations. To determine whether ovariectomy alters the concentration of TGF-beta in rat long bones, female Sprague-Dawley rats were either sham-operated (n = 19) or ovariectomized (n = 19), pair-fed a semisynthetic diet for 6 weeks, and sacrificed. Tibial and femoral diaphyses were removed and extracted by demineralization. Ovariectomy lowered serum estrogen; did not alter body weight, serum magnesium, or serum 1,25-dihydroxyvitamin D; and produced only modest differences in serum calcium and phosphate concentrations. Hydroxyproline was higher and extractable protein was lower in bones from ovariectomized rats than in bones from sham-operated rats; calcium content did not differ between the two groups of animals. Ovariectomy lowered the concentration of TGF-beta in bone but did not change the concentration of insulin-like growth factors I or II compared with values in bone from control animals. The reduction of bone TGF-beta was evident 6 weeks after surgery but not at 3 weeks. Treatment of ovariectomized rats with estrogen eliminated the TGF-beta deficit. To determine whether 17 beta-estradiol increased TGF-beta production by normal bone cells, mouse osteoblasts were treated for 2 days with 17 beta-estradiol. The production of TGF-beta was increased almost 2-fold by 1 nM 17 beta-estradiol, and short-term treatment stimulated the intracellular accumulation of TGF-beta 1 mRNA. We conclude that ovariectomy reduces deposition of TGF-beta in rat bone and that diminished skeletal TGF-beta could play a role in the pathogenesis of bone loss, fractures, and microfractures that occur in estrogen-deficient states. Our results support the possibility that estrogen and bone TGF-beta may be necessary for normal maintenance of the skeleton in female rats.<\/jats:p>","DOI":"10.1073\/pnas.89.24.12190","type":"journal-article","created":{"date-parts":[[2006,5,31]],"date-time":"2006-05-31T08:14:57Z","timestamp":1149063297000},"page":"12190-12193","update-policy":"https:\/\/doi.org\/10.1073\/pnas.cm10313","source":"Crossref","is-referenced-by-count":100,"title":["Ovariectomy selectively reduces the concentration of transforming growth factor beta in rat bone: implications for estrogen deficiency-associated bone loss."],"prefix":"10.1073","volume":"89","author":[{"given":"R D","family":"Finkelman","sequence":"first","affiliation":[{"name":"Department of Periodontics, Loma Linda University, CA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"N H","family":"Bell","sequence":"additional","affiliation":[{"name":"Department of Periodontics, Loma Linda University, CA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D D","family":"Strong","sequence":"additional","affiliation":[{"name":"Department of Periodontics, Loma Linda University, CA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L M","family":"Demers","sequence":"additional","affiliation":[{"name":"Department of Periodontics, Loma Linda University, CA."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"D J","family":"Baylink","sequence":"additional","affiliation":[{"name":"Department of Periodontics, Loma Linda University, CA."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"341","published-online":{"date-parts":[[1992,12,15]]},"container-title":["Proceedings of the National Academy of Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/pnas.org\/doi\/pdf\/10.1073\/pnas.89.24.12190","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2022,4,13]],"date-time":"2022-04-13T13:33:07Z","timestamp":1649856787000},"score":1,"resource":{"primary":{"URL":"https:\/\/pnas.org\/doi\/full\/10.1073\/pnas.89.24.12190"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1992,12,15]]},"references-count":0,"journal-issue":{"issue":"24","published-print":{"date-parts":[[1992,12,15]]}},"alternative-id":["10.1073\/pnas.89.24.12190"],"URL":"https:\/\/doi.org\/10.1073\/pnas.89.24.12190","relation":{},"ISSN":["0027-8424","1091-6490"],"issn-type":[{"value":"0027-8424","type":"print"},{"value":"1091-6490","type":"electronic"}],"subject":[],"published":{"date-parts":[[1992,12,15]]},"assertion":[{"value":"1992-12-15","order":2,"name":"published","label":"Published","group":{"name":"publication_history","label":"Publication History"}}]}}