Taste receptors in the gastrointestinal tract. V. Acid sensing in the gastrointestinal tract.
Luminal acidity is a physiological challenge in the foregut, and acidosis can occur throughout the gastrointestinal tract as a result of inflammation or ischemia. These conditions are surveyed by an elaborate network of acid-governed mechanisms to maintain homeostasis. Deviations from physiological values of extracellular pH are monitored by multiple acid sensors expressed by epithelial cells and sensory neurons. Acid-sensing ion channels are activated by moderate acidification, whereas transient receptor potential ion channels of the vanilloid subtype are gated by severe acidosis. Some ionotropic purinoceptor ion channels and two-pore domain background K(+) channels are also sensitive to alterations of extracellular pH.
Holzer
Peter
P
Research Unit of Translational Neurogastroenterology, Department of Experimental and Clinical Pharmacology, Medical University of Graz, Graz, Austria. peter.holzer@meduni-graz.at
D062565:Acid Sensing Ion Channels; D000138:Acidosis / Q000378:metabolism / Q000503:physiopathology; D000143:Acids / Q000378:metabolism*; D000818:Animals; D002628:Chemoreceptor Cells / Q000502:physiology*; D041981:Gastrointestinal Tract / Q000502:physiology* / Q000503:physiopathology; D006801:Humans; D008565:Membrane Proteins / Q000502:physiology; D009419:Nerve Tissue Proteins / Q000502:physiology; D015222:Sodium Channels / Q000502:physiology; D050916:TRPV Cation Channels / Q000502:physiology
D062565:Acid Sensing Ion Channels; D000143:Acids; D008565:Membrane Proteins; D009419:Nerve Tissue Proteins; D015222:Sodium Channels; D050916:TRPV Cation Channels