TY - JOUR T1 - Hypertension induced by chronic intermittent hypoxia: Effects of carvedilol in a rat model JF - European Respiratory Journal JO - Eur Respir J DO - 10.1183/13993003.congress-2015.OA294 VL - 46 IS - suppl 59 SP - OA294 AU - Lucilia N. Diogo AU - Sofia A. Pereira AU - Ana R. Nunes AU - Ricardo A. Afonso AU - Ana I. Santos AU - Emilia C. Monteiro Y1 - 2015/09/01 UR - http://erj.ersjournals.com/content/46/suppl_59/OA294.abstract N2 - Chronic intermittent hypoxia (CIH) and hypertension are closely related conditions. In studies performed with animal models of CIH, antihypertensive drugs were just used as pharmacological tools and the experiments were not planned to first induce hypertension and further evaluate the efficacy of drugs. We aimed to investigate in a rat model of CIH-induced hypertension, the efficacy of three different doses of carvedilol, a nonselective beta-blocker with intrinsic anti- α1-adrenergic activity. Experiments were performed in 31 male Wistar rats, aged 2-3 months, with mean body weight 308.4±45.36 g. Rats were housed individually with indwelling blood pressure telemeters and the cages were kept in a atmosphere controlled by an OxyCycler AT series, which gradually lowered oxygen in the chamber from 21% to 5% O2. Animals were exposed during their sleep period to 5.6 CIH cycles/h, 10.5 h/day, for 60 days. Carvedilol administration, by gavage, started at day 36 of CIH period and lasted 25 days. Statistical significance for all tests was set at the level of p<0.05. We found that CIH significantly increased mean arterial pressure (MAP), diastolic and systolic BP (p<0.05, for all variables) in our animal model, while no effect was observed for heart rate (HR). In addition, despite the doses of 10, 30 and 50 mg/Kg of carvedilol promoted a significant reduction in HR (p<0.05, for all doses), no decrease in MAP was observed. In conclusion, our results showed the lack of efficacy of carvedilol in reversing hypertension induced by CIH in our animal model, suggesting that the blockade of sympathetic nervous system alone does not seem to be the best strategy to revert this particular type of hypertension. ER -