Associação entre administração de Dehidroepiandrosterona (DHEA) e treinamento físico aeróbio sobre parâmetros hemodinâmicos e controle autonômico cardiovascular em ratos wistar

Abstract

Dehydroepiandrosterone (DHEA) and its sulfated ester (DHEAS) decrease serum concentrations with age and studies have shown a strong association between these concentrations and the occurrence of cardiovascular diseases. The aim of the present study was to evaluate the association between chronic administration of DHEA with cardiovascular autonomic function and its interaction with physical training in Wistar rats. To perform the work, 32 rats (± 18 weeks of age) underwent or not DHEA administration, as well as participation or not in a swimming protocol for eight consecutive weeks resulting in four experimental groups: sedentary control group (GCS, n = 8), trained control group (GCT, n = 8), sedentary DHEA group (GDS, n = 8) and trained DHEA group (GDT, n = 8). Blood pressure (BP), heart rate (HR), HR variability (HRV), and systolic (DBPV) and diastolic (DBPV) variability in time and frequency were recorded at baseline. Then, the baroreflex sensitivity and cardiac autonomic tonus test were performed. In addition, concentrations of nitric oxide (NO) and cardiac muscle weights, as well as epididymal, retroperitoneal and visceral fat were measured. In the results, we found a lower body mass gain in GDS and lower values of epididymal, retroperitoneal and visceral fat in relation to the other groups (p <0.05). HRV was higher in GDS compared to GCS, associated with higher normalized HF values (p <0.05). VBP was lower in GDS compared to the other groups, associated with reduced LF values (p <0.05). In addition, sympathetic effect (ES) was lower in GDS than in GCS and GCT (p <0.05). Concentrations of cardiac NO were higher in GDS than in GDT (p <0.05). Thus, we conclude that the chronic administration of DHEA alone is related to the improvement of the cardiac function, triggering a reduction in HR and an increase in cardiac parasympathetic activity and a decrease in VBP variance, however, physical training combined with administration was not able potentiate these effects.