{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,3,6]],"date-time":"2026-03-06T00:52:18Z","timestamp":1772758338811,"version":"3.50.1"},"reference-count":0,"publisher":"Wiley","issue":"1","license":[{"start":{"date-parts":[[1984,8,1]],"date-time":"1984-08-01T00:00:00Z","timestamp":460166400000},"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":[[1984,8]]},"abstract":"<jats:p>Membrane currents were recorded from voltage\u2010clamped, EGTA\u2010loaded muscle fibres under conditions where currents through ordinary Na+, K+ and Cl\u2010 channels were prevented by drugs or by absence of permeant ions (K+, and Cl\u2010). At 10 mM\u2010external [Ca2+], substitution of Na+ for the large and presumably impermeant organic cations tetramethyl\u2010 (TMA+) or tetraethylammonium (TEA+) failed to increase peak inward current. Hence the Ca2+ channel was not significantly permeable to Na+ under these conditions. When external [Ca2+] was reduced to levels below 1 microM in the presence of external Na+, step depolarizations to negative potentials produced tetrodotoxin\u2010resistant inward currents. At \u201020 mV, they rose to a peak of 30\u2010200 microA\/cm2 within 150 ms and declined thereafter. Ca2+ and several other divalent cations reversibly blocked this inward current. The sequence of blocking potencies was Ca2+ greater than Sr2+ greater than or equal to Co2+ greater than Mn2+ congruent to Cd2+ greater than Ni2+ congruent to Mg2+. Large inward currents may be carried by Li+, Na+, K+, Rb+ and Cs+ but not by TMA+ and TEA+. The effect of external Ca2+ ([Ca2+]o) was explored over a 10(8)\u2010fold range in concentrations. Na+ was present at a fixed concentration. When [Ca2+]o was gradually increased from 10(\u201010) to 10(\u20102) M, inward current first diminished 10\u2010fold, reached a minimum at [Ca2+]o = 60 microM and then increased again as [Ca2+]o was increased further and Ca2+ itself became a current carrier. Block of inward current at [Ca2+]o less than 10(\u20105) M could be described by binding of a single Ca2+ to a site, with a dissociation constant of the order of 0.7 microM at \u201020 mV.<\/jats:p>","DOI":"10.1113\/jphysiol.1984.sp015351","type":"journal-article","created":{"date-parts":[[2014,12,19]],"date-time":"2014-12-19T06:49:08Z","timestamp":1418971748000},"page":"565-583","source":"Crossref","is-referenced-by-count":212,"title":["A non\u2010selective cation conductance in frog muscle membrane blocked by micromolar external calcium ions."],"prefix":"10.1113","volume":"353","author":[{"given":"W","family":"Almers","sequence":"first","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"E W","family":"McCleskey","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]},{"given":"P T","family":"Palade","sequence":"additional","affiliation":[],"role":[{"role":"author","vocabulary":"crossref"}]}],"member":"311","published-online":{"date-parts":[[1984,8]]},"container-title":["The Journal of Physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/api.wiley.com\/onlinelibrary\/tdm\/v1\/articles\/10.1113%2Fjphysiol.1984.sp015351","content-type":"unspecified","content-version":"vor","intended-application":"text-mining"},{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/pdf\/10.1113\/jphysiol.1984.sp015351","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,10,20]],"date-time":"2023-10-20T03:50:46Z","timestamp":1697773846000},"score":1,"resource":{"primary":{"URL":"https:\/\/physoc.onlinelibrary.wiley.com\/doi\/10.1113\/jphysiol.1984.sp015351"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1984,8]]},"references-count":0,"journal-issue":{"issue":"1","published-print":{"date-parts":[[1984,8]]}},"alternative-id":["10.1113\/jphysiol.1984.sp015351"],"URL":"https:\/\/doi.org\/10.1113\/jphysiol.1984.sp015351","archive":["Portico"],"relation":{},"ISSN":["0022-3751","1469-7793"],"issn-type":[{"value":"0022-3751","type":"print"},{"value":"1469-7793","type":"electronic"}],"subject":[],"published":{"date-parts":[[1984,8]]}}}