Molecular physiology of proton transduction in nociceptors

Abstract

Recent cloning efforts have identified families of ion channels that may be involved in signaling noxious proton accumulation in tissue. Some conduct potassium ions outward and are closed by excess protons, others are opened under this condition carrying cations inward and their putative function is in their name ('acid sensing'), and again another channel is truly polymodal, the capsaicin receptor, sensing acid and heat. Further heat-activated channels, not yet cloned, may not be gated by protons but sensitized so strongly that they open at the command of body temperature. In either case, the result may be pain from tissue acidosis.