Role of transient receptor potential A1 in gastric nociception.
Afferent fibers innervating the gastrointestinal tract have major roles in consciously evoked sensations including pain. However, little is known about the molecules involved in mechanonociception from the upper gastrointestinal tract. We recently reported that activation of extracellular signal-regulated kinase 1/2 (ERK1/2), a member of the mitogen-activated protein kinase cascade in primary afferent neurons, was induced by noxious gastric distention in the rat, and that the activation of ERK1/2 in dorsal root ganglion (DRG) neurons can be implicated in acute visceral pain. Transient receptor potential (TRP) A1, a member of the TRP family of cation channels, was expressed in both DRG and nodose ganglion (NG) neurons innervating the stomach and in nerve fibers in the gastric wall. TRPA1 was coexpressed with ERK1/2 in gastric primary afferent neurons, and attenuation of TRPA1 activation using antisense peptides and a specific blocker led to suppression of both ERK1/2 activation and visceromotor responses. TRPA1 also significantly colocalized with substance P (SP) and calcitonin gene-related peptide (CGRP) in the thoracolumbar DRG, NG and stomach. These data indicate that SP and CGRP may also be released by TRPA1 activation in primary afferent neurons to elicit neurogenic inflammation and promote visceral hyperalgesia.
Kondo
Takashi
T
Division of Upper Gastroenterology, Hyogo College of Medicine, Hyogo 663-8501, Japan.
Oshima
Tadayuki
T
Obata
Koichi
K
Sakurai
Jun
J
Knowles
Charles H
CH
Matsumoto
Takayuki
T
Noguchi
Koichi
K
Miwa
Hiroto
H
D000818:Animals; D002070:Butadienes; D003714:Denervation; D004789:Enzyme Activation; D004791:Enzyme Inhibitors; D048049:Extracellular Signal-Regulated MAP Kinases / Q000378:metabolism; D005727:Ganglia, Spinal / Q000378:metabolism; D013271:Gastric Dilatation / Q000378:metabolism* / Q000503:physiopathology; D005753:Gastric Mucosa / Q000378:metabolism*; D008297:Male; D020078:Neurogenic Inflammation / Q000378:metabolism*; D009570:Nitriles; D009619:Nociceptors / Q000378:metabolism*; D009620:Nodose Ganglion / Q000378:metabolism; D020319:Oligodeoxyribonucleotides, Antisense; D051381:Rats; D017207:Rats, Sprague-Dawley; D013270:Stomach / Q000294:innervation / Q000503:physiopathology; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels / Q000378:metabolism*
D002070:Butadienes; D004791:Enzyme Inhibitors; D009570:Nitriles; D020319:Oligodeoxyribonucleotides, Antisense; D000074025:TRPA1 Cation Channel; D050052:TRPC Cation Channels; C480976:Trpa1 protein, rat; C113580:U 0126; D048049:Extracellular Signal-Regulated MAP Kinases