title: Sensor Mechanism and Afferent Signal Transduction of the Urinary Bladder: Special Focus on transient receptor potential Ion Channels.
abstract: In the urine storage phase, mechanical stretch stimulates bladder afferents. These urinary bladder afferent sensory nerves consist of small diameter Aδ- and C-fibers running in the hypogastic and pelvic nerves. Neuroanatomical studies have revealed a complex neuronal network within the bladder wall. The exact mechanisms that underline mechano-sensory transduction in bladder afferent terminals remain ambiguous; however, a wide range of ion channels (e.g. TTX-resistant Na(+) channels, Kv channels and hyperpolarization-activated cyclic nucleotidegated cation channels, degenerin/epithelial Na+ channel), and receptors (e.g. TRPV1, TRPM8, TRPA1, P2X2/3, etc.) have been identified at bladder afferent terminals and have implicated in the generation and modulation of afferent signals, which are elcited by a wide range of bladder stimulations including physiological bladder filling, noxious distension, cold, chemical irritation and inflammation. The mammalian transient receptor potential (TRP) family consists of 28 channels that can be subdivided into six different classes: TRPV (Vanilloid), TRPC (Canonical), TRPM (Melastatin), TRPP (Polycystin), TRPML (Mucolipin), and TRPA (Ankyrin). TRP channels are activated by a diversity of physical (voltage, heat, cold, mechanical stress) or chemical (pH, osmolality) stimuli and by binding of specific ligands, enabling them to act as multifunctional sensors at the cellular level. TRPV1, TRPV2, TRPV4, TRPM8, and TRPA1 have been described in different parts of the urogenital tract. Although only TRPV1 among TRPs has been extensively studied so far, more evidence is slowly accumulating about the role of other TRP channels, ion channels, and receptors in the pathophysiology of the urogenital tract, and may provide a new strategy for the treatment of bladder dysfunction.
authors.affiliation: Department of Urology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Yamanashi, JapanDepartment of Urology, The First Affiliated Hospital, China Medical University, Shenyang, ChinaDepartment of Urology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Masayuki
authors.initials: M
authors.lastname: Takeda
authors.affiliation: Department of Urology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Yamanashi, JapanDepartment of Urology, The First Affiliated Hospital, China Medical University, Shenyang, ChinaDepartment of Urology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Tsutomu
authors.initials: T
authors.lastname: Mochizuki
authors.affiliation: Department of Urology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Yamanashi, JapanDepartment of Urology, The First Affiliated Hospital, China Medical University, Shenyang, ChinaDepartment of Urology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Mitsuharu
authors.initials: M
authors.lastname: Yoshiyama
authors.affiliation: Department of Urology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Yamanashi, JapanDepartment of Urology, The First Affiliated Hospital, China Medical University, Shenyang, ChinaDepartment of Urology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Hiroshi
authors.initials: H
authors.lastname: Nakagomi
authors.affiliation: Department of Urology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Yamanashi, JapanDepartment of Urology, The First Affiliated Hospital, China Medical University, Shenyang, ChinaDepartment of Urology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Hideki
authors.initials: H
authors.lastname: Kobayashi
authors.affiliation: Department of Urology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Yamanashi, JapanDepartment of Urology, The First Affiliated Hospital, China Medical University, Shenyang, ChinaDepartment of Urology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Norifumi
authors.initials: N
authors.lastname: Sawada
authors.affiliation: Department of Urology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Yamanashi, JapanDepartment of Urology, The First Affiliated Hospital, China Medical University, Shenyang, ChinaDepartment of Urology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Hidenori
authors.initials: H
authors.lastname: Zakohji
authors.affiliation: Department of Urology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Yamanashi, JapanDepartment of Urology, The First Affiliated Hospital, China Medical University, Shenyang, ChinaDepartment of Urology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Shuqi
authors.initials: S
authors.lastname: DU
authors.affiliation: Department of Urology, Interdisciplinary Graduate School of Medicine & Engineering, University of Yamanashi, Yamanashi, JapanDepartment of Urology, The First Affiliated Hospital, China Medical University, Shenyang, ChinaDepartment of Urology, Shiga University of Medical Science, Shiga, Japan.
authors.forename: Isao
authors.initials: I
authors.lastname: Araki
keywords: epithelium; ion channel; sensory; transient receptor potential (TRP); urinary bladder