Digitoxin improves cardiovascular autonomic control in rats with heart failure

Author(s)

Fardin, Nubia Mantovan ^[1] ; Antonio, Ednei Luiz ^[2] ; Silva Montemor, Jairo Augusto ^[2] ; da Veiga, Glaucia Luciano ^[1] ; Ferreira Tucci, Paulo Jose ^[2] ; Campos, Ruy R. ^[1]

Affiliation

^[1] Univ Fed Sao Paulo, Dept Physiol, Escola Paulista Med, Div Cardiovasc, Rua Botucatu 862, BR-04023060 Sao Paulo, SP - Brazil

^[2] Univ Fed Sao Paulo, Dept Med, Div Cardiol, Sao Paulo, SP - Brazil

• Document type: Journal article
• Source: Canadian Journal of Physiology and Pharmacology; v. 94, n. 6, p. 643-650, JUN 2016.
• Web of Science Citations: 0

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). Weobserved 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 +/- 5ms(2), n = 8) and a decreased high frequency band (HFb: 77 +/- 5ms(2), n = 8) compared with the sham group (LFb: 14 +/- 3ms(2); HFb: 86 +/- 3ms(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. (AU)

• FAPESP's process: 09/54225-8 - The pathophysiology of congestive heart failure: from the organ to tile molecules
• Grantee: Paulo Jose Ferreira Tucci
• Support Opportunities: Research Projects - Thematic Grants