{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2025,11,3]],"date-time":"2025-11-03T09:08:04Z","timestamp":1762160884416},"reference-count":0,"publisher":"Canadian Science Publishing","issue":"8","license":[{"start":{"date-parts":[[1983,8,1]],"date-time":"1983-08-01T00:00:00Z","timestamp":428544000000},"content-version":"tdm","delay-in-days":0,"URL":"http:\/\/www.nrcresearchpress.com\/page\/about\/CorporateTextAndDataMining"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Can. J. Physiol. Pharmacol."],"published-print":{"date-parts":[[1983,8,1]]},"abstract":"<jats:p> A method is described for preparation of large amounts of a plasma membrane (PM) enriched fraction from the smooth muscle of dog antrum. It consists of preparing microsomes, treating them with ATP\u2002+\u2002EGTA\u2002+\u2002Mg, centrifuging in 30% sucrose and then centrifuging the resulting supernatant in 15% sucrose to yield the plasma membrane enriched fraction P6. The subcellular fractions obtained at various steps during purification were characterized by: 5\u2032-nucleotidase and phosphodiesterase 1 as plasma membrane markers; cytochrome c oxidase as an inner mitochondrial marker; NADPH-cytochrome c reductase as a putative endoplasmic reticulum marker; electron microscopy; polyacrylamide sodium dodecyl sulfate slab gel electrophoresis. The distribution of ATP-dependent and independent Ca uptake in presence and absence of azide and the effect of 5\u2002mM oxalate or 25\u2002mM phosphate on this uptake was also examined. The fraction P6 consists of mostly smooth surface vesicles 164.3\u2002\u00b1\u20027.2\u2002nm in diameter, has an exclusion volume of 9.7\u2002\u03bcL\/mg for [<jats:sup>3<\/jats:sup>H]inulin and 11.1\u2002\u03bcL\/mg for [<jats:sup>3<\/jats:sup>H]sucrose. P6 is maximally enriched in the ATP-dependent azide-insensitive Ca-uptake capacity and as compared with the postnuclear supernatant (SI) it shows a very small percent stimulation by oxalate and phosphate. The ATP-dependent Ca uptake by the P6 fraction occurs optimally at pH 7.0\u20137.4 and is much larger than the ATP-independent Ca uptake. At pH 7.1, the ATP-dependent Ca uptake occurs with a K<jats:sub>m<\/jats:sub> of 0.27\u2002\u03bcM and a Hill coefficient &gt;2 for Ca<jats:sup>2+<\/jats:sup>. Half maximum binding of Ca<jats:sup>2+<\/jats:sup> occurred at 300\u2002\u03bcM Ca<jats:sup>2+<\/jats:sup>. Ca ionophores A23187 and ionomycin inhibited the ATP-dependent Ca uptake, and if added after the uptake, these caused a release of the accumulated Ca<jats:sup>2+<\/jats:sup>. From these and other data it is concluded that this PM preparation contains a Ca transport system which can lead to formation of &gt;1000-fold Ca<jats:sup>2+<\/jats:sup> concentration gradient across the vesicle membrane in 1\u2002min when extravesicular Ca<jats:sup>2+<\/jats:sup> concentration is 0.3\u2002\u03bcM. Thus this preparation is an extremely useful material for studying the mechanism of action of the Ca pump in smooth muscle plasma membrane. <\/jats:p>","DOI":"10.1139\/y83-139","type":"journal-article","created":{"date-parts":[[2011,4,24]],"date-time":"2011-04-24T04:52:39Z","timestamp":1303620759000},"page":"927-940","source":"Crossref","is-referenced-by-count":5,"title":["Studies on canine gastric antrum smooth muscle: preparation and characterization of a plasma membrane enriched fraction"],"prefix":"10.1139","volume":"61","author":[{"given":"A. K.","family":"Grover","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P.","family":"Oakes","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"S. N.","family":"Sipos","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"C. Y.","family":"Kwan","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"R. E.","family":"Garfield","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"155","container-title":["Canadian Journal of Physiology and Pharmacology"],"original-title":[],"language":"en","link":[{"URL":"http:\/\/www.nrcresearchpress.com\/doi\/pdf\/10.1139\/y83-139","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2020,1,5]],"date-time":"2020-01-05T11:22:18Z","timestamp":1578223338000},"score":1,"resource":{"primary":{"URL":"http:\/\/www.nrcresearchpress.com\/doi\/10.1139\/y83-139"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1983,8,1]]},"references-count":0,"journal-issue":{"issue":"8","published-print":{"date-parts":[[1983,8,1]]}},"alternative-id":["10.1139\/y83-139"],"URL":"https:\/\/doi.org\/10.1139\/y83-139","relation":{},"ISSN":["0008-4212","1205-7541"],"issn-type":[{"value":"0008-4212","type":"print"},{"value":"1205-7541","type":"electronic"}],"subject":[],"published":{"date-parts":[[1983,8,1]]}}}