title: Sidestream cigarette smoke effects on cardiovascular responses in conscious rats: involvement of oxidative stress in the fourth cerebral ventricle.
abstract: BACKGROUND
  Cigarette exposure increases brain oxidative stress. The literature showed that increased brain oxidative stress affects cardiovascular regulation. However, no previous study investigated the involvement of brain oxidative stress in animals exposed to cigarette and its relationship with cardiovascular regulation. We aimed to evaluate the effects of central catalase inhibition on baroreflex and cardiovascular responses in rats exposed to sidestream cigarette smoke (SSCS).
  
  
  METHODS
  We evaluated males Wistar rats (320-370 g), which were implanted with a stainless steel guide cannula into the fourth cerebral ventricle (4th V). Femoral artery and vein were cannulated for mean arterial pressure (MAP) and heart rate (HR) measurement and drug infusion, respectively. Rats were exposed to SSCS during three weeks, 180 minutes, 5 days/week (CO: 100-300 ppm). Baroreflex was tested with a pressor dose of phenylephrine (PHE, 8 μg/kg, bolus) to induce bradycardic reflex and a depressor dose of sodium nitroprusside (SNP, 50 μg/kg, bolus) to induce tachycardic reflex. Cardiovascular responses were evaluated before, 5, 15, 30 and 60 minutes after 3-amino-1,2,4-triazole (ATZ, catalase inhibitor, 0.001 g/100 μL) injection into the 4th V.
  
  
  RESULTS
  Central catalase inhibition increased basal HR in the control group during the first 5 minutes. SSCS exposure increased basal HR and attenuated bradycardic peak during the first 15 minutes.
  
  
  CONCLUSIONS
  We suggest that SSCS exposure affects cardiovascular regulation through its influence on catalase activity.
authors.affiliation: Programa de Pós-Graduação em Fisioterapia, Faculdade de Ciências e Tecnologia, Universidade Estadual Paulista, UNESP, Presidente Prudente, SP, Brazil. vitor.valenti@gmail.com
authors.forename: Vitor E
authors.initials: VE
authors.lastname: Valenti
authors.forename: Luiz Carlos
authors.initials: LC
authors.lastname: de Abreu
authors.forename: Monica A
authors.initials: MA
authors.lastname: Sato
authors.forename: Celso
authors.initials: C
authors.lastname: Ferreira
authors.forename: Fernando
authors.initials: F
authors.lastname: Adami
authors.forename: Fernando L A
authors.initials: FL
authors.lastname: Fonseca
authors.forename: Valdelias
authors.initials: V
authors.lastname: Xavier
authors.forename: Moacir
authors.initials: M
authors.lastname: Godoy
authors.forename: Carlos B
authors.initials: CB
authors.lastname: Monteiro
authors.forename: Luiz Carlos M
authors.initials: LC
authors.lastname: Vanderlei
authors.forename: Paulo H N
authors.initials: PH
authors.lastname: Saldiva
mesh_terms: D000818:Animals; D017704:Baroreflex / Q000187:drug effects* / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects*; D002374:Catalase / Q000037:antagonists & inhibitors*; D020546:Fourth Ventricle / Q000187:drug effects* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects*; D008297:Male; D009599:Nitroprusside / Q000494:pharmacology; D018384:Oxidative Stress / Q000187:drug effects*; D010656:Phenylephrine / Q000494:pharmacology; D051381:Rats; D017208:Rats, Wistar; D014028:Tobacco Smoke Pollution / Q000009:adverse effects*; D014662:Vasoconstrictor Agents / Q000494:pharmacology; D014665:Vasodilator Agents / Q000494:pharmacology
chemical_list: D014028:Tobacco Smoke Pollution; D014662:Vasoconstrictor Agents; D014665:Vasodilator Agents; D009599:Nitroprusside; D010656:Phenylephrine; D002374:Catalase