L, P-/Q- and T-type Ca channels in smooth muscle cells from human umbilical artery

The electrophysiological and pharmacological properties of Ca 2+ current (I Ca ) were determined by the whole-cell configuration of the patch-clamp technique in smooth muscle cells from human umbilical artery. Using 5 mM extracellular Ca 2+ , depolarizing step pulses from -60 to 50 mV from a holding...

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Autores principales: Salemme, Silvia Verónica, Rebolledo, Alejandro, Speroni Aguirre, Francisco, Petruccelli, Silvana, Milesi, María Verónica
Formato: Articulo
Lenguaje:Inglés
Publicado: 2007
Materias:
Biología
Human umbilical artery
Patch clamp
Ca2+ channels
Acceso en línea:http://sedici.unlp.edu.ar/handle/10915/83236
Aporte de:
SEDICI (UNLP) de Universidad Nacional de La Plata
id I19-R120-10915-83236
record_format dspace
spelling I19-R120-10915-832362024-06-14T18:52:43Z http://sedici.unlp.edu.ar/handle/10915/83236 L, P-/Q- and T-type Ca channels in smooth muscle cells from human umbilical artery Salemme, Silvia Verónica Rebolledo, Alejandro Speroni Aguirre, Francisco Petruccelli, Silvana Milesi, María Verónica 2007 2019-10-15T13:50:40Z en Biología Human umbilical artery Patch clamp Ca2+ channels The electrophysiological and pharmacological properties of Ca 2+ current (I Ca ) were determined by the whole-cell configuration of the patch-clamp technique in smooth muscle cells from human umbilical artery. Using 5 mM extracellular Ca 2+ , depolarizing step pulses from -60 to 50 mV from a holding membrane potential of -80 mV evoked an I Ca which activated at membrane potentials more positive than -50 mV and exhibited a maximum current density in a range of 10-20 mV. Steady-state inactivation protocols using a V test of 10 mV gave a voltage at one-half inactivation and a slope factor of -35.6 mV and 9.5 mV, respectively. Nifedipine (1 μM), an L-type Ca 2+ channels antagonist, completely inhibited I Ca , while the L-type Ca 2+ channels agonist Bay-K 8644 (1 μM) significantly increased I Ca amplitude. Moreover, the selective blocker of P-/Q-type Ca 2+ channels ω-agatoxin IVA partially blocked I Ca (about 40 % inhibition at +20 mV by 20 nM). These pharmacological results suggest that L- and P-/Q-type Ca 2+ channels, both nifedipine-sensitive, underlie the I Ca registered using low extracellular Ca 2+ . The presence of the P-/Q-type Ca 2+ channels was confirmed by immunoblot analysis. When I Ca was recorded in a high concentration (30 mM) of extracellular Ca 2+ or Ba 2+ as current carrier, it was evident the presence of a nifedipine-insensitive component which completely inactivated during the course of the voltage-step (75 ms) at all potentials tested, and was blocked by the T-type Ca 2+ channels blocker mibefradil (10 μM). Summarizing, this work shows for the first time the electrophysiological and pharmacological properties of voltage-activated Ca 2+ currents in human umbilical artery smooth muscle cells. Facultad de Ciencias Exactas Centro de Investigación y Desarrollo en Criotecnología de Alimentos Articulo Articulo http://creativecommons.org/licenses/by-nc-sa/4.0/ Creative Commons Attribution-NonCommercial-ShareAlike 4.0 International (CC BY-NC-SA 4.0) application/pdf 55-64
institution Universidad Nacional de La Plata
institution_str I-19
repository_str R-120
collection SEDICI (UNLP)
language Inglés
topic Biología
Human umbilical artery
Patch clamp
Ca2+ channels
spellingShingle Biología
Human umbilical artery
Patch clamp
Ca2+ channels
Salemme, Silvia Verónica
Rebolledo, Alejandro
Speroni Aguirre, Francisco
Petruccelli, Silvana
Milesi, María Verónica
L, P-/Q- and T-type Ca channels in smooth muscle cells from human umbilical artery
topic_facet Biología
Human umbilical artery
Patch clamp
Ca2+ channels
description The electrophysiological and pharmacological properties of Ca 2+ current (I Ca ) were determined by the whole-cell configuration of the patch-clamp technique in smooth muscle cells from human umbilical artery. Using 5 mM extracellular Ca 2+ , depolarizing step pulses from -60 to 50 mV from a holding membrane potential of -80 mV evoked an I Ca which activated at membrane potentials more positive than -50 mV and exhibited a maximum current density in a range of 10-20 mV. Steady-state inactivation protocols using a V test of 10 mV gave a voltage at one-half inactivation and a slope factor of -35.6 mV and 9.5 mV, respectively. Nifedipine (1 μM), an L-type Ca 2+ channels antagonist, completely inhibited I Ca , while the L-type Ca 2+ channels agonist Bay-K 8644 (1 μM) significantly increased I Ca amplitude. Moreover, the selective blocker of P-/Q-type Ca 2+ channels ω-agatoxin IVA partially blocked I Ca (about 40 % inhibition at +20 mV by 20 nM). These pharmacological results suggest that L- and P-/Q-type Ca 2+ channels, both nifedipine-sensitive, underlie the I Ca registered using low extracellular Ca 2+ . The presence of the P-/Q-type Ca 2+ channels was confirmed by immunoblot analysis. When I Ca was recorded in a high concentration (30 mM) of extracellular Ca 2+ or Ba 2+ as current carrier, it was evident the presence of a nifedipine-insensitive component which completely inactivated during the course of the voltage-step (75 ms) at all potentials tested, and was blocked by the T-type Ca 2+ channels blocker mibefradil (10 μM). Summarizing, this work shows for the first time the electrophysiological and pharmacological properties of voltage-activated Ca 2+ currents in human umbilical artery smooth muscle cells.
format Articulo
Articulo
author Salemme, Silvia Verónica
Rebolledo, Alejandro
Speroni Aguirre, Francisco
Petruccelli, Silvana
Milesi, María Verónica
author_facet Salemme, Silvia Verónica
Rebolledo, Alejandro
Speroni Aguirre, Francisco
Petruccelli, Silvana
Milesi, María Verónica
author_sort Salemme, Silvia Verónica
title L, P-/Q- and T-type Ca channels in smooth muscle cells from human umbilical artery
title_short L, P-/Q- and T-type Ca channels in smooth muscle cells from human umbilical artery
title_full L, P-/Q- and T-type Ca channels in smooth muscle cells from human umbilical artery
title_fullStr L, P-/Q- and T-type Ca channels in smooth muscle cells from human umbilical artery
title_full_unstemmed L, P-/Q- and T-type Ca channels in smooth muscle cells from human umbilical artery
title_sort l, p-/q- and t-type ca channels in smooth muscle cells from human umbilical artery
publishDate 2007
url http://sedici.unlp.edu.ar/handle/10915/83236
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AT speroniaguirrefrancisco lpqandttypecachannelsinsmoothmusclecellsfromhumanumbilicalartery
AT petruccellisilvana lpqandttypecachannelsinsmoothmusclecellsfromhumanumbilicalartery
AT milesimariaveronica lpqandttypecachannelsinsmoothmusclecellsfromhumanumbilicalartery
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