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Differential Expression of Large-Conductance Ca(2+)-Activated K Channels in the Carotid Body between DBA/2J and A/J Strains of Mice
The carotid body (CB) is a primary chemosensory organ for arterial hypoxia. Inhibition of K channels in chemosensory glomus cells (GCs) are considered to be responsible for hypoxic chemoreception and/or chemotransduction of the CB. Hypoxic sensitivity of large-conductance calcium-activated K (BK) ch...
Autores principales: | , , , , |
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Formato: | Online Artículo Texto |
Lenguaje: | English |
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Frontiers Research Foundation
2011
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Materias: | |
Acceso en línea: | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3190176/ https://www.ncbi.nlm.nih.gov/pubmed/22013411 http://dx.doi.org/10.3389/fncel.2011.00019 |
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author | Otsubo, Toshiki Kostuk, Eric W. Balbir, Alexander Fujii, Koichi Shirahata, Machiko |
author_facet | Otsubo, Toshiki Kostuk, Eric W. Balbir, Alexander Fujii, Koichi Shirahata, Machiko |
author_sort | Otsubo, Toshiki |
collection | PubMed |
description | The carotid body (CB) is a primary chemosensory organ for arterial hypoxia. Inhibition of K channels in chemosensory glomus cells (GCs) are considered to be responsible for hypoxic chemoreception and/or chemotransduction of the CB. Hypoxic sensitivity of large-conductance calcium-activated K (BK) channels has been established in the rat CB. Our previous work has shown the BK channel β2 subunits are more expressed in the CB of the DBA/2J mouse than that of the A/J mouse. Because the DBA/2J mouse is more sensitive to hypoxia than the A/J mouse, our general hypothesis is that BK channels play a role in the sensitivity of the mouse CB to mild hypoxia. We performed vigorous analysis of the gene expression of α, β2, and β4 subunits of BK channels in the CB. We found that α and β2 subunits were expressed more in the CB of the DBA/2J mice than that of the A/J mice. No differences were found in the β4 subunit expression. These differences were not seen in the neighboring tissues, the superior cervical ganglion and the carotid artery, suggesting that the differences are CB specific. Further, the sensitivity of BK channels in GCs to mild hypoxia was examined in patch clamp experiments using undissociated CBs. Iberiotoxin significantly inhibited K current of GCs in the DBA/2J mice, but not in the A/J mice. When reducing PO(2) to ∼70 mmHg, K current reversibly decreased in GCs of the DBA/2J, but not of the A/J mice. In the presence of iberiotoxin, mild hypoxia did not inhibit K current in either strains. Thus, the data suggest that BK channels in GCs of the DBA/2J mice are sensitive to mild hypoxia. Differential expression of BK channel β subunits in the CBs may, at least in part, explain the different hypoxic sensitivity in these mouse strains. |
format | Online Article Text |
id | pubmed-3190176 |
institution | National Center for Biotechnology Information |
language | English |
publishDate | 2011 |
publisher | Frontiers Research Foundation |
record_format | MEDLINE/PubMed |
spelling | pubmed-31901762011-10-19 Differential Expression of Large-Conductance Ca(2+)-Activated K Channels in the Carotid Body between DBA/2J and A/J Strains of Mice Otsubo, Toshiki Kostuk, Eric W. Balbir, Alexander Fujii, Koichi Shirahata, Machiko Front Cell Neurosci Neuroscience The carotid body (CB) is a primary chemosensory organ for arterial hypoxia. Inhibition of K channels in chemosensory glomus cells (GCs) are considered to be responsible for hypoxic chemoreception and/or chemotransduction of the CB. Hypoxic sensitivity of large-conductance calcium-activated K (BK) channels has been established in the rat CB. Our previous work has shown the BK channel β2 subunits are more expressed in the CB of the DBA/2J mouse than that of the A/J mouse. Because the DBA/2J mouse is more sensitive to hypoxia than the A/J mouse, our general hypothesis is that BK channels play a role in the sensitivity of the mouse CB to mild hypoxia. We performed vigorous analysis of the gene expression of α, β2, and β4 subunits of BK channels in the CB. We found that α and β2 subunits were expressed more in the CB of the DBA/2J mice than that of the A/J mice. No differences were found in the β4 subunit expression. These differences were not seen in the neighboring tissues, the superior cervical ganglion and the carotid artery, suggesting that the differences are CB specific. Further, the sensitivity of BK channels in GCs to mild hypoxia was examined in patch clamp experiments using undissociated CBs. Iberiotoxin significantly inhibited K current of GCs in the DBA/2J mice, but not in the A/J mice. When reducing PO(2) to ∼70 mmHg, K current reversibly decreased in GCs of the DBA/2J, but not of the A/J mice. In the presence of iberiotoxin, mild hypoxia did not inhibit K current in either strains. Thus, the data suggest that BK channels in GCs of the DBA/2J mice are sensitive to mild hypoxia. Differential expression of BK channel β subunits in the CBs may, at least in part, explain the different hypoxic sensitivity in these mouse strains. Frontiers Research Foundation 2011-10-11 /pmc/articles/PMC3190176/ /pubmed/22013411 http://dx.doi.org/10.3389/fncel.2011.00019 Text en Copyright © 2011 Otsubo, Kostuk, Balbir, Fujii and Shirahata. http://www.frontiersin.org/licenseagreement This is an open-access article subject to a non-exclusive license between the authors and Frontiers Media SA, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and other Frontiers conditions are complied with. |
spellingShingle | Neuroscience Otsubo, Toshiki Kostuk, Eric W. Balbir, Alexander Fujii, Koichi Shirahata, Machiko Differential Expression of Large-Conductance Ca(2+)-Activated K Channels in the Carotid Body between DBA/2J and A/J Strains of Mice |
title | Differential Expression of Large-Conductance Ca(2+)-Activated K Channels in the Carotid Body between DBA/2J and A/J Strains of Mice |
title_full | Differential Expression of Large-Conductance Ca(2+)-Activated K Channels in the Carotid Body between DBA/2J and A/J Strains of Mice |
title_fullStr | Differential Expression of Large-Conductance Ca(2+)-Activated K Channels in the Carotid Body between DBA/2J and A/J Strains of Mice |
title_full_unstemmed | Differential Expression of Large-Conductance Ca(2+)-Activated K Channels in the Carotid Body between DBA/2J and A/J Strains of Mice |
title_short | Differential Expression of Large-Conductance Ca(2+)-Activated K Channels in the Carotid Body between DBA/2J and A/J Strains of Mice |
title_sort | differential expression of large-conductance ca(2+)-activated k channels in the carotid body between dba/2j and a/j strains of mice |
topic | Neuroscience |
url | https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3190176/ https://www.ncbi.nlm.nih.gov/pubmed/22013411 http://dx.doi.org/10.3389/fncel.2011.00019 |
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