Aerobic physical training increases contractile response and reduces cardiac fibrosis in rats subjected to early ovarian hormone deprivation

Author(s)

Felix, Ana Carolina S. ^[1] ; Dutra, Sabrina G. V. ^[1] ; Tezini, Geisa C. S. V. ^[1] ; Simoes, Marcus Vinicius ^[2] ; Dutra de Souza, Hugo Celso ^[1]

Affiliation

^[1] Univ Sao Paulo, Ribeirao Preto Med Sch, Dept Physiol, BR-14049900 Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Ribeirao Preto Med Sch, Div Cardiol, BR-14049900 Ribeirao Preto, SP - Brazil

• Document type: Journal article
• Source: Journal of Applied Physiology; v. 118, n. 10, p. 1276-1285, MAY 15 2015.
• Web of Science Citations: 8

Abstract

We investigated the effects of early ovarian hormone deprivation on the heart and the role of physical training in this condition using different approaches: cardiac autonomic tone, contractility, morphology and function, and cardiac fibrosis. Female Wistar rats (n = 48) were assigned into two groups: ovariectomized (Ovx; 10-wk-old) and control rats (Sham; 10-wk-old). Each group was further divided into two subgroups, sedentary and trained (aerobic training by swimming for 10 wk). The sedentary groups showed similar cardiac autonomic tone values; however, only the Sham group had an increase in vagal participation for the determination of the basal heart rate after physical training. The contractile responses to cardiac beta-agonists of the sedentary groups were similar, including an increased response to a beta(1)-agonist (dobutamine) observed after physical training. The Ovx sedentary group presented changes in cardiac morphology, which resulted in decreases in the ejection fraction, fractional shortening, and cardiac index compared with the Sham sedentary group. Physical training did little to alter these findings. Moreover, histology analysis showed a significant increase in cardiac fibrosis in the sedentary Ovx group, which was not observed in the trained Ovx group. We conclude that early ovarian hormone deprivation in rats impairs autonomic control, cardiac morphology, and cardiac function and increases cardiac fibrosis; however, it does not affect the contractility induced by dobutamine and salbutamol. Furthermore, this model of physical training prevented an increase in fibrosis and promoted an increase in the cardiac contractile response but had little effect on cardiac autonomic control or morphological and functional parameters. (AU)

• FAPESP's process: 08/10929-9 - Experimental study comparing the effects of early and physiological estrogen deficiency on cardiovascular control - the role of hormone replacement and aerobic physical training
• Grantee: Hugo Celso Dutra de Souza
• Support Opportunities: Regular Research Grants
• FAPESP's process: 14/01937-9 - Longitudinal study of hemodynamic, morphological and functional cardiac adaptations in rats submitted to early and physiological ovarian failure: effect of blockade of angiotensin converting enzyme and aerobic exercise
• Grantee: Hugo Celso Dutra de Souza
• Support Opportunities: Regular Research Grants