{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,11]],"date-time":"2025-09-11T06:37:10Z","timestamp":1757572630796},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"3","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1970,7,1]]},"abstract":"<jats:p>1. The effects of graded doses of oestradiol-17\u03b2 and actinomycin D, administered separately or together, on the amino acid-incorporation activity in vitro and the cytoplasmic concentration in vivo of uterine polyribosomes are described. Preparations of polyribosomes isolated from uteri of ovariectomized adult rats were determined for cytoplasmic concentration in vivo and assayed for [14C]leucine-incorporation activity in the cell-free system, exactly as described by Teng &amp; Hamilton (1967b). 2. A minimal dose of 10\u03bcg of oestradiol-17\u03b2 administered for 10h was found to increase, by about 100%, both the amino acid-incorporation activity in vitro and the cytoplasmic concentration in vivo of the polyribosomes. A minimal dose of 250\u03bcg of actinomycin D administered for 10h was found to inhibit, by about 50%, the incorporation activity in vitro of the polyribosomes. All doses of the inhibitor administered for 10h failed to alter the cytoplasmic concentration in vivo of the polyribosomes. 3. A dose of 10\u03bcg of oestradiol-17\u03b2 restored to the control value the inhibitory effect of a dose of either 50 or 125\u03bcg of actinomycin D on the activity in vitro of the polyribosomes, at 10h after treatment with the inhibitor and the hormone. In these experiments, there was an increase of 60\u2013100% in the cytoplasmic concentration in vivo of the polyribosomes. 4. A dose of 125\u03bcg of actinomycin D, administered to animals along with 10\u03bcg of oestradiol-17\u03b2 for 6\u201336h, abolished the hormone-induced enhancement of the incorporation activity in vitro, but did not prevent an increase of about 200% in the cytoplasmic concentration in vivo of the polyribosomes. However, treatment with 750\u03bcg of the inhibitor abolished both stimulatory effects of the hormone. 5. The results reported indicate that the stimulatory effects of oestradiol-17\u03b2 in vivo on the number and activity of the cytoplasmic polyribosomes in the uterus of the ovariectomized rat have different sensitivities to actinomycin D, but the primary molecular mechanisms responsible for the results are unknown. The major conclusion drawn is that the formation and appearance in the cytoplasm of newly formed polyribosomes are important features of the early action of oestrogen in the uterus.<\/jats:p>","DOI":"10.1042\/bj1180341","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T19:28:37Z","timestamp":1439234917000},"page":"341-346","update-policy":"http:\/\/dx.doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":7,"title":["Regulation of polyribosome formation and protein synthesis in the uterus. Effect of administration of graded doses of oestradiol-17\u03b2 and actinomycin D on the amino acid-incorporation activity <i>in vitro<\/i> and the cytoplasmic concentration <i>in vivo<\/i> of polyribosomes"],"prefix":"10.1042","volume":"118","author":[{"given":"Ching-Sung","family":"Teng","sequence":"first","affiliation":[{"name":"Department of Zoology, University of Texas, Austin, Tex. 78712, U.S.A."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"Terrell H.","family":"Hamilton","sequence":"additional","affiliation":[{"name":"Department of Zoology, University of Texas, Austin, Tex. 78712, U.S.A."}],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/118\/3\/341\/768122\/bj1180341.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/118\/3\/341\/768122\/bj1180341.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,26]],"date-time":"2021-11-26T19:15:52Z","timestamp":1637954152000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/118\/3\/341\/17482\/Regulation-of-polyribosome-formation-and-protein"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1970,7,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1970,7,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj1180341","relation":{},"ISSN":["0306-3283"],"issn-type":[{"value":"0306-3283","type":"print"}],"subject":[],"published":{"date-parts":[[1970,7,1]]}}}