{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,19]],"date-time":"2026-08-19T17:33:17Z","timestamp":1787160797832,"version":"build-2736575974"},"reference-count":0,"publisher":"American Physiological Society","issue":"1","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Cell Physiology"],"published-print":{"date-parts":[[1987,1,1]]},"abstract":"<jats:p>As a first step in understanding the cellular basis of maternal-fetal calcium transfer, we examined the characteristics of calcium uptake by a highly purified preparation of the syncytiotrophoblast basal (fetal facing) plasma membrane. In the presence of nanomolar concentrations of free calcium, basal membranes demonstrated substantial ATP-dependent calcium uptake [K0.5 = 119 nM, maximum velocity (Vmax) = 2 nM X min-1 X mg-1]. This uptake required magnesium, was not significantly affected by Na+ or K+ (50 mM), or sodium azide (10 mM). Intravesicular calcium was rapidly and completely released by the calcium ionophore A23187. Calcium transport was significantly stimulated by the calcium-dependent regulatory protein calmodulin. Placental membrane fractions enriched in endoplasmic reticulum (ER) and mitochondria also demonstrated ATP-dependent calcium uptake. In contrast to basal membrane, mitochondrial calcium uptake was completely inhibited by azide. The rate of calcium uptake by the ER was only 20% of that of basal membranes. We conclude that the placental basal plasma membrane possesses a high-affinity calcium transport system similar to that found in plasma membranes of a variety of cell types. This transporter is situated to permit it to function in vivo in maternal-fetal calcium transfer.<\/jats:p>","DOI":"10.1152\/ajpcell.1987.252.1.c38","type":"journal-article","created":{"date-parts":[[2017,12,24]],"date-time":"2017-12-24T04:42:44Z","timestamp":1514090564000},"page":"C38-C46","source":"Crossref","is-referenced-by-count":70,"title":["ATP-dependent calcium transport across basal plasma membranes of human placental trophoblast"],"prefix":"10.1152","volume":"252","author":[{"given":"G. J.","family":"Fisher","sequence":"first","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"L. K.","family":"Kelley","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C. H.","family":"Smith","sequence":"additional","affiliation":[],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"24","container-title":["American Journal of Physiology-Cell Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.physiology.org\/doi\/pdf\/10.1152\/ajpcell.1987.252.1.C38","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,6,17]],"date-time":"2024-06-17T15:52:11Z","timestamp":1718639531000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.physiology.org\/doi\/10.1152\/ajpcell.1987.252.1.C38"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1987,1,1]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1987,1,1]]}},"alternative-id":["10.1152\/ajpcell.1987.252.1.C38"],"URL":"https:\/\/doi.org\/10.1152\/ajpcell.1987.252.1.c38","relation":{},"ISSN":["0363-6143","1522-1563"],"issn-type":[{"value":"0363-6143","type":"print"},{"value":"1522-1563","type":"electronic"}],"subject":[],"published":{"date-parts":[[1987,1,1]]}}}