Involvement of the endogenous hydrogen sulfide/Ca(v) 3.2 T-type Ca2+ channel pathway in cystitis-related bladder pain in mice.
OBJECTIVE
Hydrogen sulfide (H(2) S), generated by enzymes such as cystathionine-γ-lyase (CSE) from L-cysteine, facilitates pain signals by activating the Ca(v) 3.2 T-type Ca(2+) channels. Here, we assessed the involvement of the CSE/H(2) S/Ca(v) 3.2 pathway in cystitis-related bladder pain.


METHODS
Cystitis was induced by i.p. administration of cyclophosphamide in mice. Bladder pain-like nociceptive behaviour was observed and referred hyperalgesia was evaluated using von Frey filaments. Phosphorylation of ERK in the spinal dorsal horn was determined immunohistochemically following intravesical administration of NaHS, an H(2) S donor.


RESULTS
Cyclophosphamide caused cystitis-related symptoms including increased bladder weight, accompanied by nociceptive changes (bladder pain-like nociceptive behaviour and referred hyperalgesia). Pretreatment with DL-propargylglycine, an inhibitor of CSE, abolished the nociceptive changes and partly prevented the increased bladder weight. CSE protein in the bladder was markedly up-regulated during development of cystitis. Mibefradil or NNC 55-0396, blockers of T-type Ca(2+) channels, administered after the symptoms of cystitis appeared, reversed the nociceptive changes. Further, silencing of Ca(v) 3.2 protein by repeated intrathecal administration of mouse Ca(v) 3.2-targeting antisense oligodeoxynucleotides also significantly attenuated the nociceptive changes, but not the increased bladder weight. Finally, the number of cells staining positive for phospho-ERK was increased in the superficial layer of the L6 spinal cord after intravesical administration of NaHS, an effect inhibited by NNC 55-0396.


CONCLUSIONS
Endogenous H(2) S, generated by up-regulated CSE, caused bladder pain and referred hyperalgesia through the activation of Ca(v) 3.2 channels, one of the T-type Ca(2+) channels, in mice with cyclophosphamide-induced cystitis.
Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, Higashi-Osaka, Japan.
Maho
M
Matsunami
Takahiro
T
Miki
Kanae
K
Nishiura
Yuko
Y
Hayashi
Yasumasa
Y
Okawa
Hiroyuki
H
Nishikawa
Fumiko
F
Sekiguchi
Lisa
L
Kubo
Tomoka
T
Ozaki
Toshifumi
T
Tsujiuchi
Atsufumi
A
Kawabata
D000083:Acetanilides / Q000494:pharmacology; D000818:Animals; D001562:Benzimidazoles / Q000494:pharmacology; D002121:Calcium Channel Blockers / Q000494:pharmacology; D020747:Calcium Channels, T-Type / Q000502:physiology*; D003520:Cyclophosphamide; D003521:Cyclopropanes / Q000494:pharmacology; D003542:Cystathionine gamma-Lyase / Q000096:biosynthesis; D003556:Cystitis / Q000139:chemically induced / Q000473:pathology / Q000503:physiopathology*; D004195:Disease Models, Animal; D005260:Female; D005727:Ganglia, Spinal / Q000378:metabolism; D006862:Hydrogen Sulfide / Q000378:metabolism*; D020748:Mibefradil / Q000494:pharmacology; D051379:Mice; D009281:Naphthalenes / Q000494:pharmacology; D009929:Organ Size / Q000187:drug effects; D010146:Pain / Q000503:physiopathology*; D011687:Purines / Q000494:pharmacology; D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels / Q000037:antagonists & inhibitors; D001743:Urinary Bladder / Q000187:drug effects / Q000378:metabolism / Q000473:pathology / Q000503:physiopathology*; D014700:Verapamil / Q000494:pharmacology
C552888:2-(1,3-dimethyl-2,6-dioxo-1,2,3,6-tetrahydro-7H-purin-7-yl)-N-(4-isopropylphenyl)acetamide; D000083:Acetanilides; D001562:Benzimidazoles; C504883:Cacna1h protein, mouse; D002121:Calcium Channel Blockers; D020747:Calcium Channels, T-Type; D003521:Cyclopropanes; D009281:Naphthalenes; D011687:Purines; D000074025:TRPA1 Cation Channel; D050051:Transient Receptor Potential Channels; C475685:Trpa1 protein, mouse; C484287:NNC 55-0396; D020748:Mibefradil; D003520:Cyclophosphamide; D014700:Verapamil; D003542:Cystathionine gamma-Lyase; D006862:Hydrogen Sulfide