{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,2]],"date-time":"2026-01-02T17:08:34Z","timestamp":1767373714613},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1993,12,1]],"date-time":"1993-12-01T00:00:00Z","timestamp":754704000000},"content-version":"vor","delay-in-days":0,"URL":"http:\/\/onlinelibrary.wiley.com\/termsAndConditions#vor"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["The Journal of Physiology"],"published-print":{"date-parts":[[1993,12]]},"abstract":"<jats:p>1. To study Ca(2+)\u2010activated K+ currents in dimethyl sulphoxide (DMSO)\u2010differentiated HL\u201060 cells (HL\u201060 granulocytes), we have combined the patch clamp technique with microfluorimetric measurements of the cytosolic free Ca2+ concentration ([Ca2+]i). 2. Elevations of [Ca2+]i induced by the receptor agonist N\u2010formyl\u2010L\u2010methionyl\u2010L\u2010phenylalanine (f\u2010MLP), by cellular spreading or by the Ca2+ ionophore ionomycin, activated whole\u2010cell currents. The kinetics of the current elevations closely paralleled the kinetics of the elevations in [Ca2+]i. Cellular spreading induced oscillations in [Ca2+]i and parallel oscillatory changes in the amplitude of the recorded currents. 3. The reversal potential of the Ca(2+)\u2010activated current was a function of the extracellular K+ concentration (56.1 mV per log [K+]), demonstrating that the underlying conductance was selective for K+. 4. The current was blocked by charybdotoxin, but insensitive to apamin. 5. The whole\u2010cell current was inwardly rectifying. No time\u2010dependent activation or inactivation of the current could be observed within the range of voltages tested (\u2010100 to +100 mV). 6. The dependence of the current amplitude on the measured [Ca2+]i revealed a half\u2010maximal activation at approximately 350 nM [Ca2+]i, and a highly co\u2010operative activation by [Ca2+]i with an apparent Hill coefficient of approximately 8. Neither the half\u2010maximal activation by [Ca2+]i nor the apparent Hill coefficient depended on the voltage, and they were identical for Ca2+ elevations caused by the ionophore and the receptor agonist. 7. Analysis of Ca(2+)\u2010activated single\u2010channel events in cell\u2010attached recordings revealed an inwardly rectifying K+ channel with a slope conductance of 35 pS. Fluctuation analysis of the Ca(2+)\u2010activated whole\u2010cell current suggested an underlying single\u2010channel conductance of a similar size (28 pS). 8. In summary, we describe a charybdotoxin\u2010sensitive, intermediate\u2010conductance Ca(2+)\u2010activated K+ channel in HL\u201060 granulocytes. The characteristics of the Ca2+ activation of this current (i.e. sensitivity to submicromolar [Ca2+]i, high co\u2010operativity and voltage independence) are similar to the Ca2+ activation of the apamin\u2010sensitive small\u2010conductance K+ channel. Our results also suggest that [Ca2+]i elevations are the predominant, if not the only, activators of this channel during physiological stimulation of HL\u201060 granulocytes.<\/jats:p>","DOI":"10.1113\/jphysiol.1993.sp019952","type":"journal-article","created":{"date-parts":[[2014,12,17]],"date-time":"2014-12-17T13:35:32Z","timestamp":1418823332000},"page":"373-390","source":"Crossref","is-referenced-by-count":19,"title":["Highly co\u2010operative Ca2+ activation of intermediate\u2010conductance K+ channels in granulocytes from a human cell line."],"prefix":"10.1113","volume":"472","author":[{"given":"P","family":"Varnai","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"N","family":"Demaurex","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"M","family":"Jaconi","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"W","family":"Schlegel","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"D P","family":"Lew","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"K H","family":"Krause","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1993,12]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1993.sp019952","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1993.sp019952","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,26]],"date-time":"2023-10-26T05:51:53Z","timestamp":1698299513000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1993.sp019952"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1993,12]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1993,12]]}},"alternative-id":["10.1113\/jphysiol.1993.sp019952"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1993.sp019952","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1993,12]]}}}