title: Spinal blockage of P/Q- or N-type voltage-gated calcium channels modulates functional and symptomatic changes related to haemorrhagic cystitis in mice.
abstract: OBJECTIVE
  Spinal voltage-gated calcium channels (VGCCs) are pivotal regulators of painful and inflammatory alterations, representing attractive therapeutic targets. We examined the effects of epidural administration of the P/Q- and N-type VGCC blockers Tx3-3 and Phα1β, respectively, isolated from the spider Phoneutria nigriventer, on symptomatic, inflammatory and functional changes allied to mouse cyclophosphamide (CPA)-induced haemorrhagic cystitis (HC). The effects of P. nigriventer-derived toxins were compared with those displayed by MVIIC and MVIIA, extracted from the cone snail Conus magus.
  
  
  METHODS
  HC was induced by a single i.p. injection of CPA (300 mg·kg(-1) ). Dose- and time-related effects of spinally administered P/Q and N-type VGCC blockers were assessed on nociceptive behaviour and macroscopic inflammation elicited by CPA. The effects of toxins were also evaluated on cell migration, cytokine production, oxidative stress, functional cystometry alterations and TRPV1, TRPA1 and NK1 receptor mRNA expression.
  
  
  RESULTS
  The spinal blockage of P/Q-type VGCC by Tx3-3 and MVIIC or N-type VGCC by Phα1β attenuated nociceptive and inflammatory events associated with HC, including bladder oxidative stress and cytokine production. CPA produced a slight increase in bladder TRPV1 and TRPA1 mRNA expression, which was reversed by all the toxins tested. Noteworthy, Phα1β strongly prevented bladder neutrophil migration, besides HC-related functional alterations, and its effects were potentiated by co-injecting the selective NK1 receptor antagonist CP-96345.
  
  
  CONCLUSIONS
  Our results shed new light on the role of spinal P/Q and N-type VGCC in bladder dysfunctions, pointing out Phα1β as a promising alternative for treating complications associated with CPA-induced HC.
authors.affiliation: Postgraduate Program in Medicine and Health Sciences, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil; Institute of Toxicology and Pharmacology, Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Rio Grande do Sul, Brazil.
authors.forename: R B M
authors.initials: RB
authors.lastname: Silva
authors.forename: N D M
authors.initials: ND
authors.lastname: Sperotto
authors.forename: E L
authors.initials: EL
authors.lastname: Andrade
authors.forename: T C B
authors.initials: TC
authors.lastname: Pereira
authors.forename: C E
authors.initials: CE
authors.lastname: Leite
authors.forename: A H
authors.initials: AH
authors.lastname: de Souza
authors.forename: M R
authors.initials: MR
authors.lastname: Bogo
authors.forename: F B
authors.initials: FB
authors.lastname: Morrone
authors.forename: M V
authors.initials: MV
authors.lastname: Gomez
authors.forename: M M
authors.initials: MM
authors.lastname: Campos
mesh_terms: D000818:Animals; D002121:Calcium Channel Blockers / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D020864:Calcium Channels, N-Type / Q000378:metabolism*; D003520:Cyclophosphamide / Q000008:administration & dosage; D003556:Cystitis / Q000139:chemically induced / Q000188:drug therapy*; D006470:Hemorrhage / Q000188:drug therapy*; D008297:Male; D051379:Mice; D009479:Neuropeptides / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D013111:Spider Venoms / Q000008:administration & dosage / Q000302:isolation & purification / Q000494:pharmacology*; D013116:Spinal Cord / Q000187:drug effects
chemical_list: D002121:Calcium Channel Blockers; D020864:Calcium Channels, N-Type; D009479:Neuropeptides; C583821:Phalpha1beta toxin, Phoneutria nigriventer; D013111:Spider Venoms; C098736:Tx3 neurotoxin; D003520:Cyclophosphamide