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(Reference retrieved automatically from Web of Science through information on FAPESP grant and its corresponding number as mentioned in the publication by the authors.)

Effects of exercise training on autonomic dysfunction management in an experimental model of menopause and myocardial infarction

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Author(s):
Flores, Lucinar J. [1] ; Figueroa, Diego [2] ; Sanches, Iris C. [1] ; Jorge, Luciana [3] ; Irigoyen, Maria-Claudia [3] ; Rodrigues, Bruno [3] ; De Angelis, Katia [1]
Total Authors: 7
Affiliation:
[1] Univ Sao Judas Tadeu, Human Movement Lab, BR-03166000 Sao Paulo - Brazil
[2] Univ Fed Rio Grande do Sul, Dept Physiol, Lab Cardiovasc Physiol, Basic & Hlth Sci Inst, Porto Alegre, RS - Brazil
[3] Univ Sao Paulo, Sch Med, Hypertens Unit, Heart Inst InCor, Sao Paulo - Brazil
Total Affiliations: 3
Document type: Journal article
Source: MENOPAUSE-THE JOURNAL OF THE NORTH AMERICAN MENOPAUSE SOCIETY; v. 17, n. 4, p. 712-717, JUL-AUG 2010.
Web of Science Citations: 20
Abstract

Objective: The aim of this study was to investigate the effects of exercise training on cardiovascular autonomic dysfunction in ovariectomized rats submitted to myocardial infarction. Methods: Female Wistar rats were divided into the following ovariectomized groups: sedentary ovariectomized (SO), trained ovariectomized (TO), sedentary ovariectomized infarcted (SOI), and trained ovariectomized infarcted (TOI). Trained groups were submitted to an exercise training protocol on a treadmill (8 wk). Arterial baroreflex sensitivity was evaluated by heart rate responses to arterial pressure changes, and cardiopulmonary baroreflex sensitivity was tested by bradycardic and hypotension responses to serotonin injection. Vagal and sympathetic effects were calculated by pharmacological blockade. Results: Arterial pressure was reduced in the TO in comparison with the SO group and increased in the TOI in relation to the SOI group. Exercise training improved the baroreflex sensitivity in both the TO and TOI groups. The TOI group displayed improvement in cardiopulmonary reflex sensitivity compared with the SOI group at the 16 mu g/kg serotonin dose. Exercise training enhanced the vagal effect in both the TO (45%) and TOI (46%) animals compared with the SO and SOI animals and reduced the sympathetic effect in the TOI (38%) in comparison with the SOI animals. Significant correlations were obtained between bradycardic baroreflex responses and vagal (r = -0.7, P < 0.005) and sympathetic (r = 0.7, P < 0.001) effects. Conclusions: These results indicate that exercise training in ovariectomized rats submitted to myocardial infarction improves resting hemodynamic status and reflex control of the circulation, which may be due to an increase in the vagal component. This suggests a homeostatic role for exercise training in reducing the autonomic impairment of myocardial infarction in postmenopausal women. (AU)