{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2023,9,16]],"date-time":"2023-09-16T18:09:06Z","timestamp":1694887746164},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"3","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1986,11,1]]},"abstract":"<jats:p>Trypsin produces a dose-related increase in cellular cyclic AMP concentration in rat thymocytes [Shneyour, Patt &amp; Trainin (1976) J. Immunol. 117, 2143-2149; Segal &amp; Ingbar (1983) Clin. Res. 31, 277A]. In the present study, I examined whether this effect of trypsin requires Ca2+ and whether it is modified by calmodulin. In fresh thymocytes suspended in standard medium (containing 1 mM-Ca2+), trypsin produced a concentration-dependent increase in cytoplasmic free Ca2+ concentration, which was evident at a concentration of 50 micrograms of trypsin\/ml and reached maximal values at about 1 mg\/ml. This effect of trypsin was very prompt in onset, almost immediate, and reached maximal values within 2-3 min. But in cells suspended in essentially Ca2+-free medium (6 nM free Ca2+), trypsin had no effect on cytoplasmic free Ca2+ concentration, which indicates that trypsin acted by increasing Ca2+ uptake rather than Ca2+ release from an intracellular pool. However, the increase in thymocyte cyclic AMP concentration produced by trypsin was independent of extracellular Ca2+ and was not influenced by calmodulin, because it was the same in the presence or absence of Ca2+ and was not changed by the calmodulin inhibitor trifluoperazine. I therefore suggest that in rat thymocytes the trypsin-induced increase in cyclic AMP concentration does not require Ca2+ and is not influenced by calmodulin.<\/jats:p>","DOI":"10.1042\/bj2390603","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T20:55:47Z","timestamp":1439240147000},"page":"603-607","update-policy":"http:\/\/dx.doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":4,"title":["Trypsin-induced increase in cyclic AMP concentration in rat thymocytes An effect independent of calcium and calmodulin"],"prefix":"10.1042","volume":"239","author":[{"given":"J","family":"Segal","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"288","container-title":["Biochemical Journal"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/239\/3\/603\/589313\/bj2390603.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/239\/3\/603\/589313\/bj2390603.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,25]],"date-time":"2021-11-25T18:26:51Z","timestamp":1637864811000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/239\/3\/603\/26031\/Trypsin-induced-increase-in-cyclic-AMP"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1986,11,1]]},"references-count":0,"journal-issue":{"issue":"3","published-print":{"date-parts":[[1986,11,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj2390603","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1986,11,1]]}}}