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Ca(2+) signaling in arterioles and small arteries of conscious, restrained, optical biosensor mice

Two-photon fluorescence microscopy and conscious, restrained optical biosensor mice were used to study smooth muscle Ca(2+) signaling in ear arterioles. Conscious mice were used in order to preserve normal mean arterial blood pressure (MAP) and sympathetic nerve activity (SNA). ExMLCK mice, which ex...

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Autores principales: Fairfax, Seth T., Mauban, Joseph R. H., Hao, Scarlett, Rizzo, Mark A., Zhang, Jin, Wier, W. Gil
Formato: Online Artículo Texto
Lenguaje:English
Publicado: Frontiers Media S.A. 2014
Materias:
Acceso en línea:https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4188025/
https://www.ncbi.nlm.nih.gov/pubmed/25339912
http://dx.doi.org/10.3389/fphys.2014.00387
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author Fairfax, Seth T.
Mauban, Joseph R. H.
Hao, Scarlett
Rizzo, Mark A.
Zhang, Jin
Wier, W. Gil
author_facet Fairfax, Seth T.
Mauban, Joseph R. H.
Hao, Scarlett
Rizzo, Mark A.
Zhang, Jin
Wier, W. Gil
author_sort Fairfax, Seth T.
collection PubMed
description Two-photon fluorescence microscopy and conscious, restrained optical biosensor mice were used to study smooth muscle Ca(2+) signaling in ear arterioles. Conscious mice were used in order to preserve normal mean arterial blood pressure (MAP) and sympathetic nerve activity (SNA). ExMLCK mice, which express a genetically-encoded smooth muscle-specific FRET-based Ca(2+) indicator, were equipped with blood pressure telemetry and immobilized for imaging. MAP was 101 ± 4 mmHg in conscious restrained mice, similar to the freely mobile state (107 ± 3 mmHg). Oscillatory vasomotion or irregular contractions were observed in most arterioles (71%), with the greatest oscillatory frequency observed at 0.25 s(−1). In a typical arteriole with an average diameter of ~35 μm, oscillatory vasomotion of a 5–6 μm magnitude was accompanied by nearly uniform [Ca(2+)] oscillations from ~0.1 to 0.5 μM, with maximum [Ca(2+)] occurring immediately before the rapid decrease in diameter. Very rapid, spatially uniform “Ca(2+) flashes” were also observed but not asynchronous propagating Ca(2+) waves. In contrast, vasomotion and dynamic Ca(2+) signals were rarely observed in ear arterioles of anesthetized exMLCK biosensor mice. Hexamethonium (30 μg/g BW, i.p.) caused a fall in MAP to 74 ± 4 mmHg, arteriolar vasodilation, and abolition of vasomotion and synchronous Ca(2+) transients. Summary: MAP and heart rate (HR) were normal during high-resolution Ca(2+) imaging of conscious, restrained mice. SNA induced continuous vasomotion and irregular vasoconstrictions via spatially uniform Ca(2+) signaling within the arterial wall. FRET-based biosensor mice and two-photon imaging provided the first measurements of [Ca(2+)] in vascular smooth muscle cells in arterioles of conscious animals.
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spelling pubmed-41880252014-10-22 Ca(2+) signaling in arterioles and small arteries of conscious, restrained, optical biosensor mice Fairfax, Seth T. Mauban, Joseph R. H. Hao, Scarlett Rizzo, Mark A. Zhang, Jin Wier, W. Gil Front Physiol Physiology Two-photon fluorescence microscopy and conscious, restrained optical biosensor mice were used to study smooth muscle Ca(2+) signaling in ear arterioles. Conscious mice were used in order to preserve normal mean arterial blood pressure (MAP) and sympathetic nerve activity (SNA). ExMLCK mice, which express a genetically-encoded smooth muscle-specific FRET-based Ca(2+) indicator, were equipped with blood pressure telemetry and immobilized for imaging. MAP was 101 ± 4 mmHg in conscious restrained mice, similar to the freely mobile state (107 ± 3 mmHg). Oscillatory vasomotion or irregular contractions were observed in most arterioles (71%), with the greatest oscillatory frequency observed at 0.25 s(−1). In a typical arteriole with an average diameter of ~35 μm, oscillatory vasomotion of a 5–6 μm magnitude was accompanied by nearly uniform [Ca(2+)] oscillations from ~0.1 to 0.5 μM, with maximum [Ca(2+)] occurring immediately before the rapid decrease in diameter. Very rapid, spatially uniform “Ca(2+) flashes” were also observed but not asynchronous propagating Ca(2+) waves. In contrast, vasomotion and dynamic Ca(2+) signals were rarely observed in ear arterioles of anesthetized exMLCK biosensor mice. Hexamethonium (30 μg/g BW, i.p.) caused a fall in MAP to 74 ± 4 mmHg, arteriolar vasodilation, and abolition of vasomotion and synchronous Ca(2+) transients. Summary: MAP and heart rate (HR) were normal during high-resolution Ca(2+) imaging of conscious, restrained mice. SNA induced continuous vasomotion and irregular vasoconstrictions via spatially uniform Ca(2+) signaling within the arterial wall. FRET-based biosensor mice and two-photon imaging provided the first measurements of [Ca(2+)] in vascular smooth muscle cells in arterioles of conscious animals. Frontiers Media S.A. 2014-10-07 /pmc/articles/PMC4188025/ /pubmed/25339912 http://dx.doi.org/10.3389/fphys.2014.00387 Text en Copyright © 2014 Fairfax, Mauban, Hao, Rizzo, Zhang and Wier. http://creativecommons.org/licenses/by/4.0/ This is an open-access article distributed under the terms of the Creative Commons Attribution License (CC BY). The use, distribution or reproduction in other forums is permitted, provided the original author(s) or licensor are credited and that the original publication in this journal is cited, in accordance with accepted academic practice. No use, distribution or reproduction is permitted which does not comply with these terms.
spellingShingle Physiology
Fairfax, Seth T.
Mauban, Joseph R. H.
Hao, Scarlett
Rizzo, Mark A.
Zhang, Jin
Wier, W. Gil
Ca(2+) signaling in arterioles and small arteries of conscious, restrained, optical biosensor mice
title Ca(2+) signaling in arterioles and small arteries of conscious, restrained, optical biosensor mice
title_full Ca(2+) signaling in arterioles and small arteries of conscious, restrained, optical biosensor mice
title_fullStr Ca(2+) signaling in arterioles and small arteries of conscious, restrained, optical biosensor mice
title_full_unstemmed Ca(2+) signaling in arterioles and small arteries of conscious, restrained, optical biosensor mice
title_short Ca(2+) signaling in arterioles and small arteries of conscious, restrained, optical biosensor mice
title_sort ca(2+) signaling in arterioles and small arteries of conscious, restrained, optical biosensor mice
topic Physiology
url https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4188025/
https://www.ncbi.nlm.nih.gov/pubmed/25339912
http://dx.doi.org/10.3389/fphys.2014.00387
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