Adipose tissue decrease by exercise training is associated with blood pressure reduction in old fructose‐fed female rats

Abstract

The aim of the present study was to investigate the effects of exercise training (ET) in old female Wistar rats (24 months old). They were ovariectomized, fed with fructose (100g/L) in drinking water and divided in 2 groups (n=6): sedentary (S) or trained (T). ET was performed on a treadmill (1 h/day; 5 days/wk for 8 wk). Glycemia, triglycerides, adipose tissue, mean blood pressure (MBP), and heart rate variability were evaluated at the end of the protocol. The metabolic results showed that ET decreased only the adipose tissue (T: 3.45±0.45 vs. S: 8.43±1.23 g). ET reduced MBP (T: 106±1.4 vs. S 117±3.8 mmHg) and increased the pulse interval variance (T:42.1±11 vs. S:33.2±5.5 ms). Cardiac sympathetic modulation (LF) was decreased in T (16.0±5.6 vs. S: 31.5±6.5 n.u.) while cardiac vagal modulation (HF) was increased (T: 84±5.6 vs. S: 68±6.5 n.u). Consequently, sympatho‐vagal balance was decreased in T (0.21±0.09) vs. S rats (0.56±0.16). A similar behavior was observed for sympathetic modulation of blood pressure (T: 5.12±1.5 vs. S: 14.9±8.1 mmHg2). Finally, we observed a direct and positive correlation between adipose tissue and MBP (r2=0.8), LF of pulse interval (r2=0.45) and LF of blood pressure (r2=0.4), while HF of pulse interval was inversely correlated (r2=0.43). In conclusion, adipose tissue decrease induced by ET is a key factor to hemodynamic benefits in old fructose‐fed female rats with ovarian hormone deprivation.