Potassium channels in human umbilical artery cells

To identify K+ channels of smooth muscle of human umbilical artery using the patch-clamp technique and to study their effect on resting tone of umbilical artery rings. Whole-cell and single-channel patch-clamp recordings in enzymatically isolated smooth muscle cells were made. Measurements of develo...

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Detalles Bibliográficos
Autores principales: Milesi, María Verónica, Raingo, Jesica, Rebolledo, Alejandro, Grassi de Gende, Ángela Ofelia
Formato: Articulo
Lenguaje:Inglés
Publicado: 2003
Materias:
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/139365
Aporte de:
id I19-R120-10915-139365
record_format dspace
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Biología
Medicina
BKCa currents
KDR currents
human umbilical artery
smooth muscle cells
spellingShingle Biología
Medicina
BKCa currents
KDR currents
human umbilical artery
smooth muscle cells
Milesi, María Verónica
Raingo, Jesica
Rebolledo, Alejandro
Grassi de Gende, Ángela Ofelia
Potassium channels in human umbilical artery cells
topic_facet Biología
Medicina
BKCa currents
KDR currents
human umbilical artery
smooth muscle cells
description To identify K+ channels of smooth muscle of human umbilical artery using the patch-clamp technique and to study their effect on resting tone of umbilical artery rings. Whole-cell and single-channel patch-clamp recordings in enzymatically isolated smooth muscle cells were made. Measurements of developed isometric force were performed on intact tissue. Delayed rectifier K+ channels (KDR) and large-conductance Ca2+-activated K+ channels (BKCa) contribute to the whole-cell voltage-and time-dependent outward K+ current, as it was specifically inhibited by 5 mM 4-aminopyridine (4-AP; KDR blocker) (92 ± 4% at 0 mV, n = 7), by 1 mM tetraethylammonium (TEA; BKCa blocker) (71 ± 4% at +60 mV, n = 4), and by 200 nM iberiotoxin (BKCa blocker) (64 ± 7% at +60 mV, n = 4). In outside-out patches, BKCa channels had ā single-channel conductance of 132 ± 4 pS (n = 24) in asymmetric K+ conditions and 216 ± 4 pS (n = 4) in a symmetric K+ gradient. The activity of the BKCa channels was significantly augmented by 1 μM Ca2+ in the inside-out configuration. 4-AP had no effect on resting tone of intact arterial rings. TEA produced contraction of arterial rings whereas phloretin, an activator of BKCa, relaxed them, which means that BKCa channels are functional in intact tissue and are involved in the maintenance of resting tone in this human vessel. The identities of K+ channels in the human umbilical artery were shown using the patch-clamp technique, and the physiologic effect of K+ channels on resting tone was documented.
format Articulo
Articulo
author Milesi, María Verónica
Raingo, Jesica
Rebolledo, Alejandro
Grassi de Gende, Ángela Ofelia
author_facet Milesi, María Verónica
Raingo, Jesica
Rebolledo, Alejandro
Grassi de Gende, Ángela Ofelia
author_sort Milesi, María Verónica
title Potassium channels in human umbilical artery cells
title_short Potassium channels in human umbilical artery cells
title_full Potassium channels in human umbilical artery cells
title_fullStr Potassium channels in human umbilical artery cells
title_full_unstemmed Potassium channels in human umbilical artery cells
title_sort potassium channels in human umbilical artery cells
publishDate 2003
url http://sedici.unlp.edu.ar/handle/10915/139365
work_keys_str_mv AT milesimariaveronica potassiumchannelsinhumanumbilicalarterycells
AT raingojesica potassiumchannelsinhumanumbilicalarterycells
AT rebolledoalejandro potassiumchannelsinhumanumbilicalarterycells
AT grassidegendeangelaofelia potassiumchannelsinhumanumbilicalarterycells
bdutipo_str Repositorios
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