Moderate intensity exercise inhibits macrophage infiltration and attenuates adipocyte inflammation in ovariectomized rats

PURPOSE The purpose of this study was to investigate the effects of the different endurance exercise intensities on the macrophage infiltration and adipocyte inflammation of ovariectomized rats. METHODS 24 female SD rats (6 weeks old) were randomly assigned to sham control (SC; n=6), ovariectomized control (OC; n=6), ovariectomized low intensity exercise (OL; n=6), and ovariectomized moderate intensity exercise (OM; n=6) groups. The two training groups ran for 60 min/day, 5 times/ week at 18 and 26m/min for 16 weeks. Twenty-four hours after the last exercise session, rats were sacrified, and epididymal pads were analyzed. F4/80 and IL-6 expressions were evaluated by western blotting. ICAM-1, VCAM-1 TLR4, TNF-α, and MCP-1 mRNA expressions were evaluated by RT-PCR. RESULTS In comparison with OC group, OM group showed significantly lower body weight gain and adipose tissue mass. Also, OM group markedly inhibited F4/80 expression, adhesion molecule (ICAM-1, VCAM-1) and pro-inflammatory cytokines (TLR4, TNF-α, MCP-1) mRNA expressions in adipose tissue. In contrast, OL group partially prevented body weight gain while other examined parameter were unaffected by low intensity exercise training. CONCLUSION The results of this study suggest that OM group inhibits visceral macrophage infiltration by suppressing the adhesion molecules. It may also attenuate cytokine production in the adipose tissue by repressing the TLR4-mediated pro-inflammatory signaling cascades in ovariectomized rats.