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The role of transient receptor potential ankyrin 1 (TRPA1) channel in activation of single unit mechanosensitive bladder afferent activities in the rat
Author(s) -
Minagawa Tomonori,
Aizawa Naoki,
Igawa Yasuhiko,
Wyndaele JeanJacques
Publication year - 2014
Publication title -
neurourology and urodynamics
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.918
H-Index - 90
eISSN - 1520-6777
pISSN - 0733-2467
DOI - 10.1002/nau.22449
Subject(s) - mechanosensitive channels , medicine , transient receptor potential channel , anesthesia , agonist , stimulation , microdialysis , pharmacology , endocrinology , receptor , central nervous system , ion channel
ABSTRACT Aims We investigated the role of transient receptor potential ankyrin 1 (TRPA1) channel on the single unit mechanosensitive afferent activities (SAAs) primarily originating from the bladder in the rat. Methods Female Sprague‐Dawley rats were used. Cystometry with continuous saline instillation was performed after intra‐venous cumulative administration of HC‐030031 (HC, a selective TRPA1 antagonist) at three doses (0.1, 1.0, and 10.0 mg/kg) in conscious rats. SAAs primarily originating from the bladder were identified by electrical stimulation of the pelvic nerve and by bladder distention, and divided by conduction velocity as Aδ‐ or C‐fibers under urethane anesthesia. The SAA‐investigation was repeated three times with cumulative HC‐administration at three doses (0.1, 1.0, and 10.0 mg/kg) or single administration of vehicle. In separate experiments, the SAA‐investigation was repeated three times with intra‐vesical instillation of allyl isothiocyanate (AI, a TRPA1 agonist, 10 µM) or vehicle with or without pretreatment with HC (1.0 mg/kg, 3 min before each intra‐vesical instillation of AI). Results There was no significant change in any cystometric parameters after HC‐administrations. A total of 54 SAAs (25 Aδ‐fibers and 29 C‐fibers) was isolated in 28 rats. SAAs of both fibers significantly decreased after HC‐administrations in a dose‐dependent manner. SAAs of both fibers significantly increased after AI‐instillations. Pretreatment with HC suppressed this excitatory effect of AI‐instillation on SAAs. Conclusions TRPA1 channel has a role in activation of mechanosensitive afferent nerve activities of both Aδ‐ and C‐fibers of the rat bladder, although its role in a physiological condition might be small. Neurourol. Urodynam. 33:544–549, 2014 . © 2013 Wiley Periodicals, Inc.