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T‐type calcium channels in carotid body oxygen sensing (889.1)
Author(s) -
Makarenko Vladislav,
Peng YingJie,
Piao Lin,
Nanduri Jayasri,
Prabhakar Nanduri
Publication year - 2014
Publication title -
the faseb journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.709
H-Index - 277
eISSN - 1530-6860
pISSN - 0892-6638
DOI - 10.1096/fasebj.28.1_supplement.889.1
Subject(s) - glomus cell , carotid body , mibefradil , hypoxia (environmental) , endocrinology , medicine , voltage dependent calcium channel , chemistry , t type calcium channel , chemoreceptor , catecholamine , calcium , electrophysiology , biology , receptor , oxygen , organic chemistry
Previous studies showed that low voltage gated T‐type Ca 2+ channels play an important role in hypoxia‐evoked catecholamine secretion from adrenal chromaffin cells. The objective of the present study was to investigate whether T‐type Ca 2+ channels contribute to hypoxic sensing by the carotid body, a key sensory organ for detecting arterial blood O 2 levels. Real time quantitative PCR analysis of rat carotid body revealed relatively high levels of α 1H as compared to α 1G and α 1I subunits of T‐type Ca 2+ channels. Immunocytochemical analysis showed much of the α 1H protein in glomus cells. Mibefradil (1µM), a T‐type Ca 2+ channel blocker significantly attenuated the carotid body sensory and glomus cell secretory and [Ca 2+ ] i responses to hypoxia. Similar attenuation of glomus cell secretory as well as [Ca 2+ ] i responses were also seen in α 1H knockout mice. These results demonstrate that T‐type Ca 2+ channels contribute to carotid body and glomus cells response to hypoxia. Grant Funding Source : Supported by NIH‐HL‐90554