{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,24]],"date-time":"2026-10-24T21:23:52Z","timestamp":1792877032131,"version":"4.5.0"},"reference-count":23,"publisher":"American Physiological Society","issue":"6","content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["American Journal of Physiology-Cell Physiology"],"published-print":{"date-parts":[[2001,12,1]]},"abstract":" The goal of the present study was to test the hypothesis that local Ca2+<\/jats:sup> release events (Ca2+<\/jats:sup> sparks) deliver high local Ca2+<\/jats:sup>concentration to activate nearby Ca2+<\/jats:sup>-sensitive K+<\/jats:sup> (BK) channels in the cell membrane of arterial smooth muscle cells. Ca2+<\/jats:sup> sparks and BK channels were examined in isolated myocytes from rat cerebral arteries with laser scanning confocal microscopy and patch-clamp techniques. BK channels had an apparent dissociation constant for Ca2+<\/jats:sup> of 19 \u03bcM and a Hill coefficient of 2.9 at \u221240 mV. At near-physiological intracellular Ca2+<\/jats:sup> concentration ([Ca2+<\/jats:sup>]i<\/jats:sub>; 100 nM) and membrane potential (\u221240 mV), the open probability of a single BK channel was low (1.2 \u00d7 10\u22126<\/jats:sup>). A Ca2+<\/jats:sup>spark increased BK channel activity to 18. Assuming that 1\u2013100% of the BK channels are activated by a single Ca2+<\/jats:sup> spark, BK channel activity increases 6 \u00d7 105<\/jats:sup>-fold to 6 \u00d7 103<\/jats:sup>-fold, which corresponds to \u223c30 \u03bcM to 4 \u03bcM spark Ca2+<\/jats:sup> concentration. 1,2-bis(2-aminophenoxy)ethane- N,N,N\u2032,N\u2032-tetraacetic acid acetoxymethyl ester caused the disappearance of all Ca2+<\/jats:sup>sparks while leaving the transient BK currents unchanged. Our results support the idea that Ca2+<\/jats:sup> spark sites are in close proximity to the BK channels and that local [Ca2+<\/jats:sup>]i<\/jats:sub> reaches micromolar levels to activate BK channels. <\/jats:p>","DOI":"10.1152\/ajpcell.2001.281.6.c1769","type":"journal-article","created":{"date-parts":[[2017,12,24]],"date-time":"2017-12-24T20:37:13Z","timestamp":1514147833000},"page":"C1769-C1775","source":"Crossref","is-referenced-by-count":191,"title":["Micromolar Ca2+<\/sup> from sparks activates Ca2+<\/sup>-sensitive K+<\/sup> channels in rat cerebral artery smooth muscle"],"prefix":"10.1152","volume":"281","author":[{"given":"Guillermo J.","family":"P\u00e9rez","sequence":"first","affiliation":[{"name":"Department of Pharmacology, University of Vermont, Burlington, Vermont 05405"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Adrian D.","family":"Bonev","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, University of Vermont, Burlington, Vermont 05405"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Mark T.","family":"Nelson","sequence":"additional","affiliation":[{"name":"Department of Pharmacology, University of Vermont, Burlington, Vermont 05405"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"24","reference":[{"key":"B1","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1986.sp016333"},{"key":"B2","doi-asserted-by":"publisher","DOI":"10.1126\/science.1373909"},{"key":"B3","doi-asserted-by":"publisher","DOI":"10.1038\/35038011"},{"key":"B4","doi-asserted-by":"publisher","DOI":"10.1152\/ajpcell.1989.257.3.C470"},{"key":"B5","doi-asserted-by":"publisher","DOI":"10.1126\/science.8235594"},{"key":"B6","doi-asserted-by":"publisher","DOI":"10.1016\/0092-8674(95)90408-5"},{"key":"B7","doi-asserted-by":"publisher","DOI":"10.1083\/jcb.52.3.690"},{"key":"B8","doi-asserted-by":"publisher","DOI":"10.1161\/01.RES.83.11.1104"},{"key":"B9","doi-asserted-by":"publisher","DOI":"10.1007\/BF00656997"},{"key":"B10","doi-asserted-by":"publisher","DOI":"10.1085\/jgp.92.2.145"},{"key":"B11","doi-asserted-by":"publisher","DOI":"10.1113\/jphysiol.1990.sp018173"},{"key":"B12","doi-asserted-by":"publisher","DOI":"10.1152\/ajpcell.2000.278.2.C235"},{"key":"B13","doi-asserted-by":"publisher","DOI":"10.1152\/ajpheart.1995.269.1.H348"},{"key":"B14","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7793.1998.199br.x"},{"key":"B15","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7793.1998.211br.x"},{"key":"B16","doi-asserted-by":"publisher","DOI":"10.1161\/01.RES.82.2.175"},{"key":"B17","doi-asserted-by":"publisher","DOI":"10.1016\/0896-6273(95)90321-6"},{"key":"B18","doi-asserted-by":"publisher","DOI":"10.1016\/S0896-6273(00)80983-6"},{"key":"B19","doi-asserted-by":"publisher","DOI":"10.1126\/science.270.5236.633"},{"key":"B20","doi-asserted-by":"publisher","DOI":"10.1085\/jgp.113.2.229"},{"key":"B22","doi-asserted-by":"publisher","DOI":"10.1007\/BF00581337"},{"key":"B23","doi-asserted-by":"publisher","DOI":"10.1111\/j.1469-7793.1998.711ba.x"},{"key":"B24","doi-asserted-by":"publisher","DOI":"10.1085\/jgp.113.2.215"}],"container-title":["American Journal of Physiology-Cell Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/journals.physiology.org\/doi\/pdf\/10.1152\/ajpcell.2001.281.6.C1769","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2024,6,17]],"date-time":"2024-06-17T19:20:40Z","timestamp":1718652040000},"score":1,"resource":{"primary":{"URL":"https:\/\/journals.physiology.org\/doi\/10.1152\/ajpcell.2001.281.6.C1769"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2001,12,1]]},"references-count":23,"journal-issue":{"issue":"6","published-print":{"date-parts":[[2001,12,1]]}},"alternative-id":["10.1152\/ajpcell.2001.281.6.C1769"],"URL":"https:\/\/doi.org\/10.1152\/ajpcell.2001.281.6.c1769","relation":{},"ISSN":["0363-6143","1522-1563"],"issn-type":[{"value":"0363-6143","type":"print"},{"value":"1522-1563","type":"electronic"}],"subject":[],"published":{"date-parts":[[2001,12,1]]}}}