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Inhibition of T-type calcium channels and hydrogen sulfide-forming enzyme reverses paclitaxel-evoked neuropathic hyperalgesia in rats.
Okubo, K; Takahashi, T; Sekiguchi, F; Kanaoka, D; Matsunami, M; Ohkubo, T; Yamazaki, J; Fukushima, N; Yoshida, S; Kawabata, A.
Afiliación
  • Okubo K; Division of Pharmacology and Pathophysiology, Kinki University School of Pharmacy, 3-4-1 Kowakae, Higashi-Osaka 577-8502, Japan.
Neuroscience ; 188: 148-56, 2011 Aug 11.
Article en En | MEDLINE | ID: mdl-21596106
Hydrogen sulfide (H2S), a gasotransmitter, facilitates pain sensation by targeting Ca(v)3.2 T-type calcium channels. The H2S/Ca(v)3.2 pathway appears to play a role in the maintenance of surgically evoked neuropathic pain. Given evidence that chemotherapy-induced neuropathic pain is blocked by ethosuximide, known to block T-type calcium channels, we examined if more selective T-type calcium channel blockers and also inhibitors of cystathionine-γ-lyase (CSE), a major H2S-forming enzyme in the peripheral tissue, are capable of reversing the neuropathic pain evoked by paclitaxel, an anti-cancer drug. It was first demonstrated that T-type calcium channel blockers, NNC 55-0396, known to inhibit Ca(v)3.1, and mibefradil inhibited T-type currents in Ca(v)3.2-transfected HEK293 cells. Repeated systemic administration of paclitaxel caused delayed development of mechanical hyperalgesia, which was reversed by single intraplantar administration of NNC 55-0396 or mibefradil, and by silencing of Ca(v)3.2 by antisense oligodeoxynucleotides. Systemic administration of dl-propargylglycine and ß-cyanoalanine, irreversible and reversible inhibitors of CSE, respectively, also abolished the established neuropathic hyperalgesia. In the paclitaxel-treated rats, upregulation of Ca(v)3.2 and CSE at protein levels was not detected in the dorsal root ganglia (DRG), spinal cord or peripheral tissues including the hindpaws, whereas H(2)S content in hindpaw tissues was significantly elevated. Together, our study demonstrates the effectiveness of NNC 55-0396 in inhibiting Ca(v)3.2, and then suggests that paclitaxel-evoked neuropathic pain might involve the enhanced activity of T-type calcium channels and/or CSE in rats, but not upregulation of Ca(v)3.2 and CSE at protein levels, differing from the previous evidence for the neuropathic pain model induced by spinal nerve cutting in which Ca(v)3.2 was dramatically upregulated in DRG.
Asunto(s)

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Paclitaxel / Canales de Calcio Tipo T / Sulfuro de Hidrógeno / Hiperalgesia / Neuralgia / Antineoplásicos Límite: Animals / Humans / Male Idioma: En Revista: Neuroscience Año: 2011 Tipo del documento: Article País de afiliación: Japón Pais de publicación: Estados Unidos

Texto completo: 1 Colección: 01-internacional Base de datos: MEDLINE Asunto principal: Paclitaxel / Canales de Calcio Tipo T / Sulfuro de Hidrógeno / Hiperalgesia / Neuralgia / Antineoplásicos Límite: Animals / Humans / Male Idioma: En Revista: Neuroscience Año: 2011 Tipo del documento: Article País de afiliación: Japón Pais de publicación: Estados Unidos