title: Extracellular Ca2+ regulates the stimulus-elicited ATP release from urothelium.
abstract: Accumulating evidence shows that the epithelial cells in urinary bladder (urothelium) serve as a sensory organ in micturition and/or in nociception pathway by releasing ATP in response to mechanical and/or chemical stimuli. Here, we compared the effects of capsaicin, acetylcholine, and prostaglandin E(2) receptor EP1 agonist (ONO-DI-004) on the urothelial ATP release in primary cultured mouse urothelial cells in low Ca(2+) medium. All of these chemicals induced a gradual ATP release from urothelium, implying that the downstream Ca(2+) release from endoplasmic reticulum could trigger the ATP release. Consistent with this suggestion, blockade of inositol 1,4,5-triphosphate receptor reduced the distention-induced ATP release from urothelial tissues. The distention-induced ATP release was not affected by tetrodotoxin. However, an increase in extracellular Ca(2+) diminished both chemical- and distention-induced ATP release from urothelium. Thus raising the extracellular Ca(2+) concentration was found to inhibit stimulation-evoked ATP urothelial release.
authors.affiliation: Department of Neurophysiology, Akita University School of Medicine, 1-1-1 Hondo, Akita, Japan. kmiyai@med.akita-u.ac.jp
authors.forename: Kazumasa
authors.initials: K
authors.lastname: Matsumoto-Miyai
authors.forename: Ai
authors.initials: A
authors.lastname: Kagase
authors.forename: Yuki
authors.initials: Y
authors.lastname: Murakawa
authors.forename: Yoshiharu
authors.initials: Y
authors.lastname: Momota
authors.forename: Masahito
authors.initials: M
authors.lastname: Kawatani
mesh_terms: D000109:Acetylcholine / Q000494:pharmacology; D000255:Adenosine Triphosphate / Q000031:analogs & derivatives / Q000378:metabolism* / Q000494:pharmacology; D000527:Alprostadil / Q000031:analogs & derivatives / Q000494:pharmacology; D000818:Animals; D002118:Calcium / Q000378:metabolism*; D002478:Cells, Cultured; D004305:Dose-Response Relationship, Drug; D004791:Enzyme Inhibitors / Q000494:pharmacology; D045604:Extracellular Fluid / Q000187:drug effects / Q000378:metabolism*; D005260:Female; D066298:In Vitro Techniques; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL; D010812:Physical Stimulation / Q000379:methods; D018709:Statistics, Nonparametric; D013997:Time Factors; D014551:Urinary Tract / Q000166:cytology / Q000254:growth & development; D019459:Urothelium / Q000187:drug effects / Q000378:metabolism*; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: C092431:6-N,N-diethyl-beta,gamma-dibromomethylene-D-ATP; D004791:Enzyme Inhibitors; C500045:ONO-DI-004; D014665:Vasodilator Agents; D000255:Adenosine Triphosphate; D000527:Alprostadil; D000109:Acetylcholine; D002118:Calcium