Mouse colon sensory neurons detect extracellular acidosis via TRPV1. Export

@article{citeulike:3787547, abstract = {Extracellular acidification contributes to pain by activating or modulating nociceptor activity. To evaluate acidic signaling from the colon, we characterized acid-elicited currents in thoracolumbar (TL) and lumbosacral (LS) dorsal root ganglion (DRG) neurons identified by content of a fluorescent dye (DiI) previously injected into the colon wall. In 13\% of unidentified LS DRG neurons (not labeled with DiI) and 69\% of LS colon neurons labeled with DiI, protons activated a sustained current that was significantly and reversibly attenuated by the transient receptor potential vanilloid receptor 1 (TRPV1) antagonist capsazepine. In contrast, 63\% of unidentified LS DRG neurons and 4\% of LS colon neurons exhibited transient amiloride-sensitive acid-sensing ion channel (ASIC) currents. The peak current density of acid-elicited currents was significantly reduced in colon sensory neurons from TRPV1-null mice, supporting predominant expression of TRPV1 in LS colon sensory neurons, which was also confirmed immunohistochemically. Similar to LS colon DRG neurons, acid-elicited currents in TL colon DRG neurons were mediated predominantly by TRPV1. However, the pH producing half-activation of responses significantly differed between TL and LS colon DRG neurons. The properties of acid-elicited currents in colon DRG neurons suggest differential contributions of ASICs and TRPV1 to colon sensation and likely nociception.}, author = {Sugiura, T. and Bielefeldt, K. and Gebhart, G. F.}, citeulike-article-id = {3787547}, citeulike-linkout-0 = {http://dx.doi.org/10.1152/ajpcell.00440.2006}, citeulike-linkout-1 = {http://view.ncbi.nlm.nih.gov/pubmed/17251322}, citeulike-linkout-2 = {http://www.hubmed.org/display.cgi?uids=17251322}, doi = {10.1152/ajpcell.00440.2006}, issn = {0363-6143}, journal = {American journal of physiology. Cell physiology}, keywords = {acidosis, colon, trpv1}, month = {May}, number = {5}, posted-at = {2008-12-14 14:34:55}, priority = {3}, title = {Mouse colon sensory neurons detect extracellular acidosis via TRPV1.}, url = {http://dx.doi.org/10.1152/ajpcell.00440.2006}, volume = {292}, year = {2007} }

TY - JOUR ID - citeulike:3787547 L3 - citeulike-article-id:3787547 N2 - Extracellular acidification contributes to pain by activating or modulating nociceptor activity. To evaluate acidic signaling from the colon, we characterized acid-elicited currents in thoracolumbar (TL) and lumbosacral (LS) dorsal root ganglion (DRG) neurons identified by content of a fluorescent dye (DiI) previously injected into the colon wall. In 13% of unidentified LS DRG neurons (not labeled with DiI) and 69% of LS colon neurons labeled with DiI, protons activated a sustained current that was significantly and reversibly attenuated by the transient receptor potential vanilloid receptor 1 (TRPV1) antagonist capsazepine. In contrast, 63% of unidentified LS DRG neurons and 4% of LS colon neurons exhibited transient amiloride-sensitive acid-sensing ion channel (ASIC) currents. The peak current density of acid-elicited currents was significantly reduced in colon sensory neurons from TRPV1-null mice, supporting predominant expression of TRPV1 in LS colon sensory neurons, which was also confirmed immunohistochemically. Similar to LS colon DRG neurons, acid-elicited currents in TL colon DRG neurons were mediated predominantly by TRPV1. However, the pH producing half-activation of responses significantly differed between TL and LS colon DRG neurons. The properties of acid-elicited currents in colon DRG neurons suggest differential contributions of ASICs and TRPV1 to colon sensation and likely nociception. IS - 5 JF - American journal of physiology. Cell physiology SN - 0363-6143 TI - Mouse colon sensory neurons detect extracellular acidosis via TRPV1. VL - 292 KW - acidosis KW - colon KW - trpv1 AU - Sugiura, T AU - Bielefeldt, K AU - Gebhart, GF PY - 2007/05// UR - http://dx.doi.org/10.1152/ajpcell.00440.2006 ER -