title: Digitoxin improves cardiovascular autonomic control in rats with heart failure.
abstract: The effects of chronic treatment with digitoxin on arterial baroreceptor sensitivity for heart rate (HR) and renal sympathetic nerve activity (rSNA) control, cardiopulmonary reflex, and autonomic HR control in an animal model of heart failure (HF) were evaluated. Wistar rats were treated with digitoxin, which was administered in their daily feed (1 mg/kg per day) for 60 days. The following 3 experimental groups were evaluated: sham, HF, and HF treated with digitoxin (HF + DIG). We observed an increase in rSNA in the HF group (190 ± 29 pps, n = 5) compared with the sham group (98 ± 14 pps, n = 5). Digitoxin treatment prevented an increase in rSNA (98 ± 14 pps, n = 7). Therefore, arterial baroreceptor sensitivity was decreased in the HF group (-1.24 ± 0.07 bpm/mm Hg, n = 8) compared with the sham group (-2.27 ± 0.23 bpm/mm Hg, n = 6). Digitoxin did not alter arterial baroreceptor sensitivity in the HF + DIG group. Finally, the HF group showed an increased low frequency band (LFb: 23 ± 5 ms(2), n = 8) and a decreased high frequency band (HFb: 77 ± 5 ms(2), n = 8) compared with the sham group (LFb: 14 ± 3 ms(2); HFb: 86 ± 3 ms(2), n = 9); the HF+DIG group exhibited normalized parameters (LFb: 15 ± 3 ms(2); HFb: 85 ± 3 ms(2), n = 9). In conclusion, the benefits of decreasing rSNA are not directly related to improvements in peripheral cardiovascular reflexes; such occurrences are due in part to changes in the central nuclei of the brain responsible for autonomic cardiovascular control.
authors.affiliation: a Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862, CEP 04023-060, São Paulo, SP, Brazil.
authors.forename: Núbia Mantovan
authors.initials: NM
authors.lastname: Fardin
authors.affiliation: b Cardiology Division, Department of Medicine, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
authors.forename: Ednei Luiz
authors.initials: EL
authors.lastname: Antonio
authors.affiliation: b Cardiology Division, Department of Medicine, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
authors.forename: Jairo Augusto Silva
authors.initials: JA
authors.lastname: Montemor
authors.affiliation: a Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862, CEP 04023-060, São Paulo, SP, Brazil.
authors.forename: Glaucia Luciano
authors.initials: GL
authors.lastname: da Veiga
authors.affiliation: b Cardiology Division, Department of Medicine, Universidade Federal de São Paulo, São Paulo, SP, Brazil.
authors.forename: Paulo José Ferreira
authors.initials: PJ
authors.lastname: Tucci
authors.affiliation: a Cardiovascular Division, Department of Physiology, Universidade Federal de São Paulo, Escola Paulista de Medicina, Rua Botucatu, 862, CEP 04023-060, São Paulo, SP, Brazil.
authors.forename: Ruy R
authors.initials: RR
authors.lastname: Campos
mesh_terms: D000818:Animals; D001341:Autonomic Nervous System / Q000187:drug effects / Q000502:physiology; D001794:Blood Pressure / Q000187:drug effects* / Q000502:physiology; D002316:Cardiotonic Agents / Q000494:pharmacology / Q000627:therapeutic use*; D004074:Digitoxin / Q000494:pharmacology / Q000627:therapeutic use*; D015150:Echocardiography, Doppler; D006333:Heart Failure / Q000000981:diagnostic imaging / Q000188:drug therapy* / Q000503:physiopathology; D006339:Heart Rate / Q000187:drug effects* / Q000502:physiology; D006439:Hemodynamics / Q000187:drug effects* / Q000502:physiology; D008297:Male; D051381:Rats; D017208:Rats, Wistar
chemical_list: D002316:Cardiotonic Agents; D004074:Digitoxin
keywords: activité nerveuse sympathique au niveau renal; analyse spectrale; baroreflex sensitivity; cardiopulmonary reflex; digitoxin; digitoxine; heart failure; insuffisance cardiaque; renal sympathetic nerve activity; réflexe cardiopulmonaire; sensibilité du baroréflexe; spectral analysis; sympathetic vasomotor tone; tonus vasomoteur sympathique