Effects of the administration of a catalase inhibitor into the fourth cerebral ventricle on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke

• Published in: Clinics (São Paulo, Brazil) Brazil), 2013-06, Vol.68 (6), p.851-857
• Main Authors: Valenti, Vitor E., de Abreu, Luiz Carlos, Fonseca, Fernando L.A., Adami, Fernando, Sato, Monica A., Vanderlei, Luiz Carlos M., Ferreira, Lucas Lima, Rodrigues, Luciano M., Ferreira, Celso
• Format: Article
• Language: English
• Subjects: Air Pollutants; Amitrole - administration & dosage; Amitrole - pharmacology; Animals; Arterial Pressure - drug effects; Baroreflex - drug effects; Basic Research; Cardiovascular System - drug effects; Catalase; Catalase - antagonists & inhibitors; Enzyme Inhibitors - administration & dosage; Enzyme Inhibitors - pharmacology; Fourth Ventricle - drug effects; Heart Rate - drug effects; Male; MEDICINE, GENERAL & INTERNAL; Medulla Oblongata; Oxidative Stress; Rats; Rats, Inbred SHR; Rats, Inbred WKY; Reactive Oxygen Species - metabolism; Reference Values; Species Specificity; Time Factors; Tobacco; Tobacco Smoke Pollution - adverse effects
• ISSN: 1807-5932; 1980-5322; 1980-5322
• DOI: 10.6061/clinics/2013(06)21

Previous studies have demonstrated a relationship between brain oxidative stress and cardiovascular regulation. We evaluated the effects of central catalase inhibition on cardiovascular responses in spontaneously hypertensive rats exposed to sidestream cigarette smoke. Male Wistar Kyoto (WKY) rats and spontaneously hypertensive rats (SH) (16 weeks old) were implanted with a stainless steel guide cannula leading into the fourth cerebral ventricle (4th V). The femoral artery and vein were cannulated for arterial pressure and heart rate measurement and drug infusion, respectively. The rats were exposed to sidestream cigarette smoke for 180 minutes/day, 5 days/week for 3 weeks (CO: 100-300 ppm). The baroreflex was tested using a pressor dose of phenylephrine (8 μg/kg, bolus) and a depressor dose of sodium nitroprusside (50 μg/kg, bolus). Cardiovascular responses were evaluated before and 5, 15, 30 and 60 minutes after injection of a catalase inhibitor (3-amino-1,2,4-triazole, 0.001 g/100 μL) into the 4th V. Vehicle administration into the 4th V did not affect the cardiovascular response, whereas administration of the central catalase inhibitor increased the basal HR and attenuated the bradycardic peak (p