Low- and high-threshold mechanosensitive afferents innervate all regions of the alimentary canal and have the ability to sensitize in response to inflammatory mediators (4,174). Their mechanosensitivity depends on the presence of sensors that detect stretch, contraction, or other mechanical deformations of the gut wall. One of these sensors, a mechanosensitive K+ channel, has been characterized by single-channel recordings from sensory neurons in the rat colon (175). DRG neurons innervating the stomach and colon exhibit stretch-sensitive calcium fluxes that are inhibited by gadolinium, a blocker of mechanosensitive ion channels
(176). Other mechanosensitive ion channels comprise ASIC1, ASIC2, ASIC3 (163-166), TRPV4
(177), and members of the KCNK channels such as TREK-2 (172). It is uncertain whether blockade of mechanosensitive ion channels is of therapeutic utility, given that mechanically triggered motor and secretory reflexes regulating digestion may also be impaired.
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