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Calcium sparks in the intact gerbil spiral modiolar artery
BACKGROUND: Calcium sparks are ryanodine receptor mediated transient calcium signals that have been shown to hyperpolarize the membrane potential by activating large conductance calcium activated potassium (BK) channels in vascular smooth muscle cells. Along with voltage-dependent calcium channels,...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
Publicado: |
BioMed Central
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3170618/ https://www.ncbi.nlm.nih.gov/pubmed/21871098 http://dx.doi.org/10.1186/1472-6793-11-15 |
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author | Krishnamoorthy, Gayathri Regehr, Keil Berge, Samantha Scherer, Elias Q Wangemann, Philine |
author_facet | Krishnamoorthy, Gayathri Regehr, Keil Berge, Samantha Scherer, Elias Q Wangemann, Philine |
author_sort | Krishnamoorthy, Gayathri |
collection | PubMed |
description | BACKGROUND: Calcium sparks are ryanodine receptor mediated transient calcium signals that have been shown to hyperpolarize the membrane potential by activating large conductance calcium activated potassium (BK) channels in vascular smooth muscle cells. Along with voltage-dependent calcium channels, they form a signaling unit that has a vasodilatory influence on vascular diameter and regulation of myogenic tone. The existence and role of calcium sparks has hitherto been unexplored in the spiral modiolar artery, the end artery that controls blood flow to the cochlea. The goal of the present study was to determine the presence and properties of calcium sparks in the intact gerbil spiral modiolar artery. RESULTS: Calcium sparks were recorded from smooth muscle cells of intact arteries loaded with fluo-4 AM. Calcium sparks occurred with a frequency of 2.6 Hz, a rise time of 17 ms and a time to half-decay of 20 ms. Ryanodine reduced spark frequency within 3 min from 2.6 to 0.6 Hz. Caffeine (1 mM) increased spark frequency from 2.3 to 3.3 Hz and prolonged rise and half-decay times from 17 to 19 ms and from 20 to 23 ms, respectively. Elevation of potassium (3.6 to 37.5 mM), presumably via depolarization, increased spark frequency from 2.4 to 3.2 Hz. Neither ryanodine nor depolarization changed rise or decay times. CONCLUSIONS: This is the first characterization of calcium sparks in smooth muscle cells of the spiral modiolar artery. The results suggest that calcium sparks may regulate the diameter of the spiral modiolar artery and cochlear blood flow. |
format | Online Article Text |
id | pubmed-3170618 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | BioMed Central |
record_format | MEDLINE/PubMed |
spelling | pubmed-31706182011-09-11 Calcium sparks in the intact gerbil spiral modiolar artery Krishnamoorthy, Gayathri Regehr, Keil Berge, Samantha Scherer, Elias Q Wangemann, Philine BMC Physiol Research Article BACKGROUND: Calcium sparks are ryanodine receptor mediated transient calcium signals that have been shown to hyperpolarize the membrane potential by activating large conductance calcium activated potassium (BK) channels in vascular smooth muscle cells. Along with voltage-dependent calcium channels, they form a signaling unit that has a vasodilatory influence on vascular diameter and regulation of myogenic tone. The existence and role of calcium sparks has hitherto been unexplored in the spiral modiolar artery, the end artery that controls blood flow to the cochlea. The goal of the present study was to determine the presence and properties of calcium sparks in the intact gerbil spiral modiolar artery. RESULTS: Calcium sparks were recorded from smooth muscle cells of intact arteries loaded with fluo-4 AM. Calcium sparks occurred with a frequency of 2.6 Hz, a rise time of 17 ms and a time to half-decay of 20 ms. Ryanodine reduced spark frequency within 3 min from 2.6 to 0.6 Hz. Caffeine (1 mM) increased spark frequency from 2.3 to 3.3 Hz and prolonged rise and half-decay times from 17 to 19 ms and from 20 to 23 ms, respectively. Elevation of potassium (3.6 to 37.5 mM), presumably via depolarization, increased spark frequency from 2.4 to 3.2 Hz. Neither ryanodine nor depolarization changed rise or decay times. CONCLUSIONS: This is the first characterization of calcium sparks in smooth muscle cells of the spiral modiolar artery. The results suggest that calcium sparks may regulate the diameter of the spiral modiolar artery and cochlear blood flow. BioMed Central 2011-08-26 /pmc/articles/PMC3170618/ /pubmed/21871098 http://dx.doi.org/10.1186/1472-6793-11-15 Text en Copyright ©2011 Krishnamoorthy et al; licensee BioMed Central Ltd. http://creativecommons.org/licenses/by/2.0 This is an Open Access article distributed under the terms of the Creative Commons Attribution License (http://creativecommons.org/licenses/by/2.0), which permits unrestricted use, distribution, and reproduction in any medium, provided the original work is properly cited. |
spellingShingle | Research Article Krishnamoorthy, Gayathri Regehr, Keil Berge, Samantha Scherer, Elias Q Wangemann, Philine Calcium sparks in the intact gerbil spiral modiolar artery |
title | Calcium sparks in the intact gerbil spiral modiolar artery |
title_full | Calcium sparks in the intact gerbil spiral modiolar artery |
title_fullStr | Calcium sparks in the intact gerbil spiral modiolar artery |
title_full_unstemmed | Calcium sparks in the intact gerbil spiral modiolar artery |
title_short | Calcium sparks in the intact gerbil spiral modiolar artery |
title_sort | calcium sparks in the intact gerbil spiral modiolar artery |
topic | Research Article |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3170618/ https://www.ncbi.nlm.nih.gov/pubmed/21871098 http://dx.doi.org/10.1186/1472-6793-11-15 |
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