%0 Journal Article
%T Sidestream cigarette smoke effects on cardiovascular responses in conscious rats: involvement of oxidative stress in the fourth cerebral ventricle
%A Vitor E Valenti
%A Luiz de Abreu
%A Monica A Sato
%A Celso Ferreira
%A Fernando Adami
%A Fernando LA Fonseca
%A Valdelias Xavier
%A Moacir Godoy
%A Carlos B Monteiro
%A Luiz Carlos M Vanderlei
%A Paulo HN Saldiva
%J BMC Cardiovascular Disorders
%D 2012
%I BioMed Central
%R 10.1186/1471-2261-12-22
%X 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 ¦Ìg/kg, bolus) to induce bradycardic reflex and a depressor dose of sodium nitroprusside (SNP, 50 ¦Ìg/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 ¦ÌL) injection into the 4th V.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.We suggest that SSCS exposure affects cardiovascular regulation through its influence on catalase activity.Exposure to environmental tobacco smoke is recognized as a significant contributor to cardiovascular mortality. The impact of ambient cigarette smoke on cardiovascular and respiratory systems may be an important factor in the observed adverse cardiovascular health effects [1-3]. Cigarette smoke is classified into two categories, the mainstream smoke usually inhaled by active smokers, and the sidestream smoke emitted from a cigarette and inhaled by so-called "passive smokers". It is known that sidestream cigarette smoke (SSCS) contains a variety of oxidants and other harmful compounds much more than that contained in mainstream smoke [4]. Passive smokers are thus exposed to almost the same chemicals in cigarette smoke as active smokers are. Therefore, passive smoking increases the risk of cardiac or other related disease in nonsmokers [5].Oxidative stress caused by cigarette smoke occurs due to the direct effects of the radicals present in
%U http://www.biomedcentral.com/1471-2261/12/22