title: Presence of the Ca2+-activated chloride channel anoctamin 1 in the urethra and its role in excitatory neurotransmission.
abstract: We investigated the cellular distribution of the calcium-activated chloride channel (CaCC), anoctamin 1, in the urethra of mice, rats, and sheep by both immunofluorescence and PCR. We studied its role in urethral contractility by examining the effects of chloride-free medium and of several CaCC inhibitors on noradrenergic and cholinergic excitatory responses, and on nitrergic relaxations in urethral preparations. In all species analyzed, CaCC played a key role in urethral contractions, influencing smooth muscle cells activated by increases in intracellular calcium, probably due to calcium influx but with a minor contribution by IP(3)-mediated calcium release. The participation of CaCC in relaxant responses was negligible. Strong anoctamin 1 immunoreactivity was detected in the smooth muscle cells and urothelia of sheep, rat, and mouse urethra, but not in the interstitial cells of Cajal (ICC) in any of these species. RT-PCR confirmed the expression of anoctamin 1 mRNA in the rat urethra. This anoctamin 1 in urethral smooth muscle probably mediates the activity of chloride in contractile responses in different species, However, the lack of anoctamin 1 in ICCs challenges its proposed role in regulating urethral contractility in a manner similar to that observed in the gut.
authors: Dept. of Physiology, Veterinary School, Madrid, Spain.
authors: Maria
authors: M
authors: Sancho
authors: Angeles
authors: A
authors: García-Pascual
authors: Domingo
authors: D
authors: Triguero
mesh_terms: D000818:Animals; D000075369:Anoctamin-1; D000894:Anti-Inflammatory Agents, Non-Steroidal / Q000494:pharmacology; D001896:Boron Compounds / Q000494:pharmacology; D018118:Chloride Channels / Q000037:antagonists & inhibitors / Q000235:genetics / Q000502:physiology*; D002712:Chlorides / Q000378:metabolism; D005260:Female; D041981:Gastrointestinal Tract / Q000502:physiology; D056885:Interstitial Cells of Cajal / Q000502:physiology*; D007537:Isometric Contraction / Q000502:physiology; D051379:Mice; D009130:Muscle, Smooth / Q000502:physiology; D009544:Niflumic Acid / Q000494:pharmacology; D009638:Norepinephrine / Q000502:physiology; D009928:Organ Specificity; D012333:RNA, Messenger / Q000378:metabolism; D051381:Rats; D017208:Rats, Wistar; D012756:Sheep; D009435:Synaptic Transmission / Q000502:physiology*; D014521:Urethra / Q000294:innervation* / Q000502:physiology*
chemical_list: C531181:ANO1 protein, mouse; C552942:ANO1 protein, rat; D000075369:Anoctamin-1; D000894:Anti-Inflammatory Agents, Non-Steroidal; D001896:Boron Compounds; D018118:Chloride Channels; D002712:Chlorides; D012333:RNA, Messenger; D009544:Niflumic Acid; C109986:2-aminoethoxydiphenyl borate; D009638:Norepinephrine