Fundamental lessons from blunted chemosensory response of carotid body to hypoxia

Resumen

Glomus cells are synaptically connected with single afferent fiber, and depolarization of the cell should result in increases of [Ca2²⁺]_i, neurosecretion and neural discharge. Suppression of K⁺ current by low PO₂ is supposed to depolarize the glomus cells. Therefore, a blunted chemosensory response can provide a clue to O₂ sensing by the cells being insensitive to O₂ But literature showed that K⁺- O₂ depression by low PO₂ was normal, although the cells did not depolarize. Also, the sensory fiber with blunted hypoxic response showed a normal or supernormal CO₂/H⁺ response. Accordingly, they should manifest normal or supernormal K⁺ current depression with raised CO₂/H⁺ stimuli.