{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,21]],"date-time":"2026-05-21T06:25:41Z","timestamp":1779344741306,"version":"3.51.4"},"reference-count":0,"publisher":"Portland Press Ltd.","issue":"2","content-domain":{"domain":["portlandpress.com"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1994,12,1]]},"abstract":"<jats:p>In single, Fura 2-loaded RBL-2H3 cells, antigen and thapsigargin depleted the same intracellular pool of Ca2+ in the absence of external Ca2+; provision of external Ca2+ induced immediate increases in levels of free Ca2+ ([Ca2+]i). These increases were dependent on the presence of external Ca2+ and, presumably, on influx of Ca2+ across the cell membrane. Both stimulants enhanced intracellular accumulation of 45Ca2+ through ostensibly similar mechanisms because accumulation was blocked to similar extents by various multivalent cations or by depolarization with K+. Because thapsigargin blocked reuptake of Ca2+ into inositol 1,4,5-trisphosphate sensitive stores, uptake occurred independently of the refilling of these stores. Uptake was dependent instead on sequestration of 45Ca2+ in a pool of high capacity that was insensitive to thapsigargin, caffeine, GTP and inositol 1,4,5-trisphosphate but sensitive to ionomycin and mitochondrial inhibitors. The existence of an inositol 1,4,5-trisphosphate-insensitive pool was also apparent in permeabilized cells; at 0.1 microM [Ca2+]i, uptake of 45Ca2+ was largely confined (&amp;gt; 80%) to the inositol 1,4,5-trisphosphate-sensitive pool, but at 2 microM [Ca2+]i uptake was largely (&amp;gt; 60%) into the inositol 1,4,5-trisphosphate-insensitive pool. Provision of mitochondrial inhibitors along with thapsigargin to block uptake into both pools, did not impair the thapsigargin-induced increase in [Ca2+]i or influx of Ca2+, as indicated by changes in Fura 2 fluorescence, but did block the intracellular accumulation of 45Ca2+. The studies illustrate the utility of simultaneous measurements of [Ca2+]i and 45Ca2+ uptake for a full accounting of Ca2+ homoeostasis as exemplified by the ability to distinguish between influx and mitochondrial uptake of Ca2+.<\/jats:p>","DOI":"10.1042\/bj3040431","type":"journal-article","created":{"date-parts":[[2015,8,10]],"date-time":"2015-08-10T21:40:39Z","timestamp":1439242839000},"page":"431-440","update-policy":"https:\/\/doi.org\/10.1042\/crossmark_policy","source":"Crossref","is-referenced-by-count":51,"title":["Antigen and thapsigargin promote influx of Ca2+ in rat basophilic RBL-2H3 cells by ostensibly similar mechanisms that allow filling of inositol 1,4,5-trisphosphate-sensitive and mitochondrial Ca2+ stores"],"prefix":"10.1042","volume":"304","author":[{"given":"H","family":"Ali","sequence":"first","affiliation":[{"name":"Laboratory of Chemical Pharmacology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1760, U.S.A."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"K","family":"Maeyama","sequence":"additional","affiliation":[{"name":"Laboratory of Chemical Pharmacology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1760, U.S.A."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R","family":"Sagi-Eisenberg","sequence":"additional","affiliation":[{"name":"Laboratory of Chemical Pharmacology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1760, U.S.A."}],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M A","family":"Beaven","sequence":"additional","affiliation":[{"name":"Laboratory of Chemical Pharmacology, National Heart, Lung, and Blood Institute, National Institutes of Health, Bethesda, MD 20892-1760, 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\/304\/2\/431\/725571\/bj3040431.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/portlandpress.com\/biochemj\/article-pdf\/304\/2\/431\/725571\/bj3040431.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2021,11,23]],"date-time":"2021-11-23T23:20:21Z","timestamp":1637709621000},"score":1,"resource":{"primary":{"URL":"https:\/\/portlandpress.com\/biochemj\/article\/304\/2\/431\/31570\/Antigen-and-thapsigargin-promote-influx-of-Ca2-in"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1994,12,1]]},"references-count":0,"journal-issue":{"issue":"2","published-print":{"date-parts":[[1994,12,1]]}},"URL":"https:\/\/doi.org\/10.1042\/bj3040431","relation":{},"ISSN":["0264-6021","1470-8728"],"issn-type":[{"value":"0264-6021","type":"print"},{"value":"1470-8728","type":"electronic"}],"subject":[],"published":{"date-parts":[[1994,12,1]]}}}