title: Hyperalgesia induced by spinal and peripheral hydrogen sulfide: evidence for involvement of Cav3.2 T-type calcium channels.
abstract: Hydrogen sulfide (H2S), a gasotransmitter, facilitates membrane currents through T-type Ca2+ channels, and intraplantar (i.pl.) administration of NaHS, a donor of H2S, causes prompt hyperalgesia in rats. In this context, we asked whether intrathecal (i.t.) administration of NaHS could mimic the hyperalgesic effect of i.pl. NaHS in rats, and then examined if Cav3.2 isoform of T-type Ca2+ channels contributed to the pro-nociceptive effects of i.t. and i.pl. NaHS. Either i.t. or i.pl. administration of NaHS rapidly decreased nociceptive threshold in rats, as determined by the paw pressure method. The hyperalgesia caused by i.t. and i.pl. NaHS was abolished by co-administration of mibefradil, a pan-T-type Ca2+ channel inhibitor, and also suppressed by pretreatment with i.t. and i.pl. zinc chloride, known to preferentially inhibit Cav3.2 among T-type Ca2+ channel isoforms, respectively. Repeated i.t. administration of antisense oligodeoxynucleotides (ODNs) targeting rat Cav3.2, but not mismatch ODNs, caused silencing of Cav3.2 protein in the dorsal root ganglia and spinal cord, and then attenuated the hyperalgesia induced by either i.t. or i.pl. NaHS. Our findings thus establish that spinal and peripheral NaHS/H2S activates or sensitizes Cav3.2 T-type Ca2+ channels expressed in the primary afferents and/or spinal nociceptive neurons, leading to sensitization of nociceptive processing and hyperalgesia.
authors.affiliation: Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan.
authors.forename: Yumi
authors.initials: Y
authors.lastname: Maeda
authors.forename: Yuka
authors.initials: Y
authors.lastname: Aoki
authors.forename: Fumiko
authors.initials: F
authors.lastname: Sekiguchi
authors.forename: Maho
authors.initials: M
authors.lastname: Matsunami
authors.forename: Tomoko
authors.initials: T
authors.lastname: Takahashi
authors.forename: Hiroyuki
authors.initials: H
authors.lastname: Nishikawa
authors.forename: Atsufumi
authors.initials: A
authors.lastname: Kawabata
mesh_terms: D000704:Analysis of Variance; D000818:Animals; D002121:Calcium Channel Blockers / Q000627:therapeutic use*; D020747:Calcium Channels, T-Type / Q000235:genetics / Q000378:metabolism*; D002531:Cerebellum / Q000378:metabolism; D004195:Disease Models, Animal; D005727:Ganglia, Spinal / Q000187:drug effects / Q000378:metabolism; D006862:Hydrogen Sulfide / Q000009:adverse effects*; D006930:Hyperalgesia / Q000139:chemically induced* / Q000188:drug therapy* / Q000378:metabolism / Q000473:pathology; D008297:Male; D020748:Mibefradil / Q000627:therapeutic use*; D020319:Oligodeoxyribonucleotides, Antisense / Q000627:therapeutic use; D017288:Pain Threshold / Q000187:drug effects / Q000502:physiology*; D051381:Rats; D017208:Rats, Wistar; D013116:Spinal Cord / Q000187:drug effects*
chemical_list: C509958:Cacna1h protein, rat; D002121:Calcium Channel Blockers; D020747:Calcium Channels, T-Type; D020319:Oligodeoxyribonucleotides, Antisense; D020748:Mibefradil; D006862:Hydrogen Sulfide