Name: ERICK ROBERTO GONÇALVES CLAUDIO
Publication date: 12/05/2017
Advisor:
Name |
Role |
|---|---|
| GLAUCIA RODRIGUES DE ABREU | Advisor * |
Examining board:
| Name |
Role |
|---|---|
| GLAUCIA RODRIGUES DE ABREU | Advisor * |
| RICHARD DIEGO LEITE | External Examiner * |
| SONIA ALVES GOUVEA | Internal Examiner * |
Summary: The aim of the present study was to evaluate the effects of the different time of exercise training (ET) initiation after myocardial infarction (MI) on the cardiac function and the ventricular remodeling in ovariectomized rats (OVX). Twelve-week-old OVX
female Wistar rats (Rattus Norvegicus Albinus) were randomly divided into four groups: MI-SHAM (SHAM), MI sedentary (MI), MI which started ET 3 days after MI (MI3+ET) and MI which started ET 15 days after MI (MI15+ET). Low to moderate intensity training protocol in a motorized treadmill was performed during 8 weeks (60 min/d, 5 days/wk). Forty-eight hours after the last training session, animals were
anesthetized and subject to evaluation of the following parameters: i) Cardiac function after a catheter insertion in the left ventricle (LV); ii) MI area; iii) collagen deposition and myocyte hypertrophy by histology; iv) myocardial oxidative stress by the in situ generation of superoxide (DHE) and by the evaluation of the advanced oxidation protein products (AOPP); v) protein expression of type 1 receptor of angiotensin II (AT-1R) and of the membrane isoform of multi-enzymatic complex of
NADPH oxidase (gp91phox) by the western blotting (WB) method; vi) antioxidants protein expression, such as superoxide dismutase (SOD-1 and SOD-2) and catalase (CAT), also by WB; vii) antioxidant enzymes activities (SOD and CAT). Eight weeks after ET it was observed in the MI3+ET group: i) there was a higher infarction area; ii)
early ET cannot improve the LV end diastolic pressure; iii) there were no
improvements in the remodeling parameters; iv) there was an increase in the expression of AT-1R in the cardiac tissue; v) ET initiated early after MI cannot reduces the cardiac oxidative stress induced by MI; vi) it was observed a reduction in the expression of SOD-2, and; vii) ET initiate early cannot restore the reduction in enzymatic activity of both antioxidant enzymes after MI. Therefore, we showed that
ET initiated 3 days after MI was not efficient in preventing the deterioration of cardiac function and adverse remodeling. These results were associated with the increase in AT-1R expression and of the higher oxidative stress. Accordingly, the time of ET initiation after MI in OVX rats is an important factor related to the prevention of MIinduced
alterations and should be taking into account for the ET prescription after MI in the condition of estrogen deficiency.
