Poor Wheel-Running Exercise Can Decrease Blood Pressure through Hormonal Control and Increase Endurance Exercise Capacity in Middle-Aged Normal Rats

The aim of this study was to examine the effects of voluntary wheel-running (WR) on body weight (BW), waist circumference, mesenteric fat mass (MFM), adipocyte size, circulating cytokines/hormones, blood pressure (BP) and exercise endurance capacity in 11-month-old normal rats. Three-week WR with about 0.2 km of daily running distance caused a gradual loss in BW despite an increased intake of food/water. MFM decreased as daily running distance increased. Moreover, there was a positive correlation between MFM and BW, waist circumference or adipocyte size. On the other hand, WR significantly decreased systolic/diastolic BPs, and increased endurance exercise capacity. WR rat sera contained lower concentrations of angiotensin II, aldosterone, vasopressin and endothelin-1 and higher concentration of brain natriuretic peptide compared with sedentary rat sera. Thus, WR-induced reduction in resting BPs may be accomplished by attenuated vasoconstriction, enhanced vasodilatation and reduction in blood volume. In addition, circulating vascular endothelial growth factor and interleukin-6 were higher in WR rats, suggesting angiogenesis, anti-inflammation and insulin-sensitization. These results support a prevalent idea that daily light-exercise is a potential strategy for preventing metabolic syndrome.