{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,16]],"date-time":"2026-07-16T10:23:16Z","timestamp":1784197396936,"version":"3.55.0"},"reference-count":0,"publisher":"Rockefeller University Press","issue":"5","content-domain":{"domain":["rupress.org"],"crossmark-restriction":true},"short-container-title":[],"published-print":{"date-parts":[[1989,5,1]]},"abstract":"<jats:p>Ionic currents of enzymatically dispersed type I and type II cells of the carotid body have been studied using the whole cell variant of the patch-clamp technique. Type II cells only have a tiny, slowly activating outward potassium current. By contrast, in every type I chemoreceptor cell studied we found (a) sodium, (b) calcium, and (c) potassium currents. (a) The sodium current has a fast activation time course and an activation threshold at approximately -40 mV. At all voltages inactivation follows a single exponential time course. The time constant of inactivation is 0.67 ms at 0 mV. Half steady state inactivation occurs at a membrane potential of approximately -50 mV. (b) The calcium current is almost totally abolished when most of the external calcium is replaced by magnesium. The activation threshold of this current is at approximately -40 mV and at 0 mV it reaches a peak amplitude in 6-8 ms. The calcium current inactivates very slowly and only decreases to 27% of the maximal value at the end of 300-ms pulses to 40 mV. The calcium current was about two times larger when barium ions were used as charge carriers instead of calcium ions. Barium ions also shifted 15-20 mV toward negative voltages the conductance vs. voltage curve. Deactivation kinetics of the calcium current follows a biphasic time course well fitted by the sum of two exponentials. At -80 mV the slow component has a time constant of 1.3 +\/- 0.4 ms whereas the fast component, with an amplitude about 20 times larger than the slow component, has a time constant of 0.16 +\/- 0.03 ms. These results suggest that type I cells have predominantly fast deactivating calcium channels. The slow component of the tails may represent the activity of a small population of slowly deactivating calcium channels, although other possibilities are considered. (c) Potassium current seems to be mainly due to the activity of voltage-dependent potassium channels, but a small percentage of calcium-activated channels may also exist. This current activates slowly, reaches a peak amplitude in 5-10 ms, and thereafter slowly inactivates. Inactivation is almost complete in 250-300 ms. The potassium current is reversibly blocked by tetraethylammonium. Under current-clamp conditions type I cells can spontaneously fire large action potentials. These results indicate that type I cells are excitable and have a variety of ionic conductances. We suggest a possible participation of these conductances in chemoreception.<\/jats:p>","DOI":"10.1085\/jgp.93.5.979","type":"journal-article","created":{"date-parts":[[2004,5,13]],"date-time":"2004-05-13T23:48:59Z","timestamp":1084492139000},"page":"979-999","update-policy":"https:\/\/doi.org\/10.1085\/jgp.crossmarkpolicy","source":"Crossref","is-referenced-by-count":72,"title":["Ionic currents in dispersed chemoreceptor cells of the mammalian carotid body."],"prefix":"10.1085","volume":"93","author":[{"given":"J","family":"Ure\u00f1a","sequence":"first","affiliation":[{"name":"Departamento de Fisiolog\u00eda y Biofisica, Facultad de Medicina, Universidad de Sevilla, Spain."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J","family":"L\u00f3pez-L\u00f3pez","sequence":"additional","affiliation":[{"name":"Departamento de Fisiolog\u00eda y Biofisica, Facultad de Medicina, Universidad de Sevilla, Spain."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"C","family":"Gonz\u00e1lez","sequence":"additional","affiliation":[{"name":"Departamento de Fisiolog\u00eda y Biofisica, Facultad de Medicina, Universidad de Sevilla, Spain."}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"J","family":"L\u00f3pez-Barneo","sequence":"additional","affiliation":[{"name":"Departamento de Fisiolog\u00eda y Biofisica, Facultad de Medicina, Universidad de Sevilla, Spain."}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"291","published-online":{"date-parts":[[1989,5,1]]},"container-title":["The Journal of general physiology"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/rupress.org\/jgp\/article-pdf\/93\/5\/979\/1813926\/979.pdf","content-type":"application\/pdf","content-version":"vor","intended-application":"syndication"},{"URL":"https:\/\/rupress.org\/jgp\/article-pdf\/93\/5\/979\/1813926\/979.pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2023,7,27]],"date-time":"2023-07-27T12:30:57Z","timestamp":1690461057000},"score":1,"resource":{"primary":{"URL":"https:\/\/rupress.org\/jgp\/article\/93\/5\/979\/27758\/Ionic-currents-in-dispersed-chemoreceptor-cells-of"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[1989,5,1]]},"references-count":0,"journal-issue":{"issue":"5","published-print":{"date-parts":[[1989,5,1]]}},"URL":"https:\/\/doi.org\/10.1085\/jgp.93.5.979","relation":{},"ISSN":["0022-1295","1540-7748"],"issn-type":[{"value":"0022-1295","type":"print"},{"value":"1540-7748","type":"electronic"}],"subject":[],"published":{"date-parts":[[1989,5,1]]}}}