title: TRPC channels and diacylglycerol dependent calcium signaling in rat sensory neurons.
abstract: Transient receptor potential (TRP) channels of the TRPV, TRPA, and TRPM subfamilies play important roles in somatosensation including nociception. While particularly the Thermo TRPs have been extensively investigated in sensory neurons, the relevance of the subclass of "canonical" TRPC channels in primary afferents is yet elusive. In the present study, we investigated the presence and contribution to Ca(2+) transients of TRPC channels in dorsal root ganglion neurons. We found that six of the seven known TRPC subtypes were expressed in lumbar DRG, with TRPC1, C3, and C6 being the most abundant. Microfluorimetric calcium measurements showed Ca(2+) influx induced by oleylacylglycerol (OAG), an activator of the TRPC3/C6/C7 subgroup. Furthermore, OAG induced rises in [Ca(2+)](i) were inhibited by SKF96365, an inhibitor of receptor and store operated calcium channel. OAG induced calcium transients were also inhibited by blockers of diacylglycerol (DAG) lipase, lipoxygenase or cyclooxygenase and, intriguingly, by inhibitors of the capsaicin receptor TRPV1. Notably, SKF96365 did not affect capsaicin-induced calcium transients. Taken together, our findings suggest that TRPC are functionally expressed in subpopulations of DRG neurons. These channels, along with TRPV1, contribute to calcium homeostasis in rat sensory neurons.
authors.affiliation: Division of Physiology, DPMP, Innsbruck Medical University, Innsbruck, Austria.
authors.forename: Michaela
authors.initials: M
authors.lastname: Kress
authors.forename: Johannes
authors.initials: J
authors.lastname: Karasek
authors.forename: Antonio V
authors.initials: AV
authors.lastname: Ferrer-Montiel
authors.forename: Nadja
authors.initials: N
authors.lastname: Scherbakov
authors.forename: Rainer Viktor
authors.initials: RV
authors.lastname: Haberberger
mesh_terms: D000818:Animals; D002118:Calcium / Q000037:antagonists & inhibitors / Q000378:metabolism*; D020013:Calcium Signaling / Q000187:drug effects*; D004075:Diglycerides / Q000037:antagonists & inhibitors / Q000494:pharmacology*; D005260:Female; D007093:Imidazoles / Q000494:pharmacology; D008071:Lipoprotein Lipase / Q000378:metabolism; D008084:Lipoxygenase / Q000378:metabolism; D011451:Prostaglandin-Endoperoxide Synthases / Q000378:metabolism; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D020133:Reverse Transcriptase Polymerase Chain Reaction; D011984:Sensory Receptor Cells / Q000187:drug effects* / Q000378:metabolism*; D050052:TRPC Cation Channels / Q000235:genetics / Q000378:metabolism*; D050916:TRPV Cation Channels / Q000378:metabolism
chemical_list: D004075:Diglycerides; D007093:Imidazoles; D012333:RNA, Messenger; D050052:TRPC Cation Channels; D050916:TRPV Cation Channels; C493922:Trpv1 protein, rat; D008084:Lipoxygenase; D011451:Prostaglandin-Endoperoxide Synthases; D008071:Lipoprotein Lipase; C063159:1-(2-(3-(4-methoxyphenyl)propoxy)-4-methoxyphenylethyl)-1H-imidazole; D002118:Calcium