Hydrogen sulfide is an oxygen sensor in the carotid body

Research output: Contribution to journalReview article

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Abstract

There is considerable controversy surrounding the initial step that transduces a fall in PO2 into a physiological signal, i.e., the "oxygen sensor" in chemoreceptors. Initial studies on systemic and respiratory vessels suggested that the metabolism of hydrogen sulfide (H 2S) could serve as the oxygen sensor. This model was subsequently extended to chemoreceptors in fish and tissues of other animals. In this model, constitutive production of biologically active H 2S is offset by H 2S oxidation; when oxygen availability falls, production of H 2S exceeds metabolism, and the resultant increase in intracellular H 2S initiates the appropriate physiological responses. This model is supported by observations that the effects of hypoxia and H 2S are similar, if not identical in many tissues: hypoxic responses are inhibited by inhibitors of H 2S biosynthesis and augmented by sulfur donating molecules, and the tipping point between H 2S production and oxidation occurs at physiologically relevant PO2s. Recent studies from other laboratories support this mechanism of O 2 sensing in the carotid body. This review summarizes information that supports the H 2S metabolic hypothesis in these tissues with emphasis on the carotid chemoreceptors. Evidence suggesting that H 2S is not involved in oxygen sensing in the carotid body is also critically evaluated.

Original languageEnglish (US)
Pages (from-to)103-110
Number of pages8
JournalRespiratory Physiology and Neurobiology
Volume179
Issue number2-3
DOIs
StatePublished - Dec 15 2011

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Keywords

  • Glomus cell
  • Hydrogen sulfide
  • Hypoxia
  • Oxygen sensing
  • Peripheral chemoreceptors

ASJC Scopus subject areas

  • Physiology
  • Pulmonary and Respiratory Medicine
  • Neuroscience(all)

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