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dc.contributor.authorUreña, J.
dc.contributor.authorLópez López, José Ramón 
dc.contributor.authorGonzález, Constancio
dc.contributor.authorLópez Barneo, José
dc.date.accessioned2017-07-26T08:42:06Z
dc.date.available2017-07-26T08:42:06Z
dc.date.issued1989
dc.identifier.citationJournal of General Physiology, 1989, vol. 93. p. 979-999es
dc.identifier.issn0022-1295es
dc.identifier.urihttp://uvadoc.uva.es/handle/10324/24724
dc.descriptionProducción Científicaes
dc.description.abstractIonic currents of enzymatically dispersed type 1 and type 11 cells of the carotid body have been studied using the whole cell variant of the patch-clamp technique. Type 11 cells only have a tiny, slowly activating outward potassium cur­ rent. By contrast, in every type 1 chemoreceptor cell studied we found (a) sodium, (b) calcium, and (e) potassium currents. (a) The sodium current has a fast activation time course and an activation threshold at --40 mV. At ali voltages inactivation follows a single exponential time course. The time constant of inactivation is 0.67 ms at O mV. Half steady state inactivation occurs at a membrane potential of --50 mV. (b) The calcium current is almost totally abolished when most of the extemal calcium is replaced by magnesium. The activation threshold of this cur­ rent is at --40 mV and at O 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 com­ ponent 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 1 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. (e) 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 5-1O ms, and thereafter slowly inactivates. Inactivation is almost complete in 250-300 ms. The potassium current is reversibly blocked by tetraeth­ ylammonium. Under current-clamp conditions type I cells can spontaneously fire large action potentials.es
dc.format.mimetypeapplication/pdfes
dc.language.isoenges
dc.publisherThe Rockefeller University Presses
dc.rights.accessRightsinfo:eu-repo/semantics/openAccesses
dc.rights.urihttp://creativecommons.org/licenses/by-nc-nd/4.0/
dc.subject.classificationCuerpo carotídeoes
dc.subject.classificationQuimiorreceptoreses
dc.subject.classificationCarotid body
dc.subject.classificationChemoreceptors
dc.titleIonic currents in dispersed chemoreceptor cells of the mammalian carotid bodyes
dc.typeinfo:eu-repo/semantics/articlees
dc.rights.holder© 1989 The Rockefeller University Press
dc.identifier.doi10.1085/jgp.93.5.979
dc.relation.publisherversionhttps://rupress.org/jgp/article/93/5/979/27758/Ionic-currents-in-dispersed-chemoreceptor-cells-of
dc.identifier.publicationfirstpage979es
dc.identifier.publicationlastpage999es
dc.identifier.publicationtitleJournal of General Physiologyes
dc.identifier.publicationvolume93es
dc.peerreviewedSIes
dc.rightsAttribution-NonCommercial-NoDerivatives 4.0 International


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