Acid-sensing by carotid body is inhibited by blockers of voltage-sensitive Ca2+ channels.

The membrane potential hypothesis that the responses to hypercapnia of carotid chemosensory activity is mediated by voltage-gated Ca2+ channels was investigated by measuring directly the chemosensory output from rat and cat carotid bodies, perfused and superfused in vitro. We found that the inorganic and organic blockers of voltage-gated Ca2+ channels suppressed the hypercapnic responses, thereby supporting the membrane potential hypothesis.