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Release of 5‐hydroxytryptamine by hypoxia from epithelioid cells of chicken thoracic aorta
Author(s) -
Ito Shigeo,
Ohta Toshio,
Nakazato Yoshikazu
Publication year - 1997
Publication title -
british journal of pharmacology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 2.432
H-Index - 211
eISSN - 1476-5381
pISSN - 0007-1188
DOI - 10.1038/sj.bjp.0701489
Subject(s) - glomus cell , hypoxia (environmental) , aorta , nifedipine , extracellular , epithelioid cell , chemoreceptor , thoracic aorta , endocrinology , biology , medicine , anatomy , calcium , chemistry , microbiology and biotechnology , receptor , immunohistochemistry , organic chemistry , oxygen
Epithelioid cells in the chicken thoracic aorta are shown to contain 5‐hydroxytryptamine (5‐HT) in immunocytochemical studies. To determine whether these cells act as chemoreceptors, as do type I cells of the carotid body, we examined the effects of hypoxia and acidosis on the release of 5‐HT from the chicken thoracic aorta. Hypoxia caused the output of 5‐HT in incubation medium. A reduction of pH to 6.8 failed to evoke 5‐HT release. The response to hypoxia was inhibited by the removal of extracellular Ca 2+ and by nifedipine and ω‐conotoxin GVIA. These results suggest that epithelioid cells in the chicken thoracic aorta are chemoreceptors which sense a decrease in P O 2 and then release 5‐HT by Ca 2+ influx through voltage‐dependent L‐ and N‐type Ca 2+ channels. The epithelioid cells in the chicken aorta may be a useful model for pharmacological and physiological studies of 5‐HT‐containing cells. British Journal of Pharmacology (1997) 122 , 799–801; doi: 10.1038/sj.bjp.0701489