{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,9,26]],"date-time":"2025-09-26T22:38:10Z","timestamp":1758926290795},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"2","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1982,2,15]]},"abstract":"<jats:p>Swine granulosa-luteal cells incubated in Ca2+-deficient medium (5 muM final Ca2+ concentration) for short time periods produced diminished quantities of progesterone in response to lutropin. Maximally stimulating effects of prostaglandin E2 and L-adrenaline were also impaired significantly. Diminished progesterone production could not be attributed to alterations in protein synthesis or cell viability. Under Ca2+-deprived conditions, the stimulatory actions of cholera toxin, 3-isobutyl-1-methylxanthine and 8-bromo cyclic AMP were also significantly impeded. Administration of a presumptive antagonist of transmembrane Ca2+ influx (verapamil) or of EGTA to chelate extracellular Ca2+, significantly decreased the total cellular content of Ca2+, and antagonized the actions of lutropin. Micromolar concentrations of trifluoperazine mimicked the suppressive effects of Ca2+ deprivation. Conversely, the bivalent-cation ionophore, ionophore A23187, significantly augmented the stimulation of progesterone produced by lutropin. Thus the present observations implicate Ca2+ in the modulation of hormonally stimulated progesterone production in isolated ovarian cells, and suggest that Ca2+ may influence one or more processes distal to, or independent of, cyclic AMP generation. In addition, the susceptibility of progesterone biosynthesis to inhibition by trifluoperazine suggests a possible role for calmodulin in the ovary.<\/jats:p>","DOI":"10.1042\/bj2020381","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T20:33:10Z","timestamp":1439238790000},"page":"381-386","update-policy":"http:\/\/dx.doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":28,"title":["Calcium ions modulate hormonally stimulated progesterone production in isolated ovarian cells"],"prefix":"10.1042","volume":"202","author":[{"given":"J D","family":"Veldhuis","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P A","family":"Klase","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/202\/2\/381\/784263\/bj2020381.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/202\/2\/381\/784263\/bj2020381.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T12:36:44Z","timestamp":1637843804000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/202\/2\/381\/13772\/Calcium-ions-modulate-hormonally-stimulated"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1982,2,15]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1982,2,15]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2020381","relation":{},"ISSN":["0306-3283"],"issn-type":[{"value":"0306-3283","type":"print"}],"subject":[],"published":{"date-parts":[[1982,2,15]]}}}