Resistance training improves hemodynamic function, collagen deposition and inflammatory profiles: experimental model of heart failure

Abstract

The role of resistance training on collagen deposition, the inflammatory profile and muscle weakness in heart failure remains unclear. Therefore, this study evaluated the influence of a resistance training program on hemodynamic function, maximum strength gain, collagen deposition and inflammatory profile in chronic heart failure rats. Thirty-two male Wistar rats submitted to myocardial infarction by coronary artery ligation or sham surgery were assigned into four groups: sedentary sham (S-Sham, n = 8); trained sham (T-Sham, n = 8); sedentary chronic heart failure (S-CHF, n = 8) and trained chronic heart failure (T-CHF, n = 8). The maximum strength capacity was evaluated by the one maximum repetition test. Trained groups were submitted to an 8-week resistance training program (4 days/week, 4 sets of 10-12 repetitions/session, at 65% to 75% of one maximum repetition). After 8 weeks of the resistance training program, the T-CHF group showed lower left ventricular end diastolic pressure (P<0.001), higher left ventricular systolic pressure (P<0.05), higher systolic blood pressure (P<0.05), an improvement in the maximal positive derivative of ventricular pressure (P<0.05) and maximal negative derivative of ventricular pressure (P<0.05) when compared to the S-CHF group; no differences were observed when compared to Sham groups. In addition, resistance training was able to reduce myocardial hypertrophy (P<0.05), left ventricular total collagen volume fraction (P<0.01), IL-6 (P<0.05), and TNF-α/IL-10 ratio (P<0.05), as well as increasing IL-10 (P<0.05) in chronic heart failure rats when compared to the S-CHF group. Eight weeks of resistance training promotes an improvement of cardiac function, strength gain, collagen deposition and inflammatory profile in chronic heart failure rats.

Figure 1. Representative illustration of the apparatus used for resistance training.

Figure 2. Absolute values for one repetition maximal test (1RM).

(A). Relative values for one repetition maximal test (1RM) (B). Values are means ± SE; n = 8 for all groups. S-Sham, sedentary sham rats; T-Sham, training sham rats; S-CHF, sedentary chronic heart failure rats; T-CHF, training chronic heart failure rats. *P<0.001 compared to sedentary groups. †P<0.01 compared to sedentary groups ‡P<0.05 compared to S-Sham group.

Figure 3. Representative images of ventricular sections stained with Picrosirius (A–D) and statistical analysis (E).

Values are means ± SE. The arrows indicate collagen detected in polarized light. A. S-Sham, sedentary sham rats (n = 7); B. T-Sham, training sham rats (n = 8); C. S-CHF, sedentary chronic heart failure rats (n = 8); D. T-CHF, training chronic heart failure rats (n = 8). *P<0.01 compared to trained groups. †P<0.001 compared with S-Sham group.

Figure 4. Plasma levels of IL-6, IL-10, TNF-α, TNF- α to IL-10 ratio and IL-6 to IL-10 ratio (A–E).

Values are means ± SE. Figure A) S-Sham, sedentary sham rats (n = 5); T-Sham, training sham rats (n = 5); S-CHF, sedentary chronic heart failure rats (n = 5); T-CHF, training chronic heart failure rats (n = 6). Figure B, C and D, n = 6 for all groups. Figure E, n = 5 for all groups. *P<0.05 compared to all groups. †P<0.05 compared to sedentary groups. ‡P<0.05 compared to trained groups.