Impact of exercise and angiotensin converting enzyme inhibition on tumor necrosis factor-α and leptin in fructose-fed hypertensive rats

The aim of this study was to evaluate the effects of moderate-intensity regular exercise and/or an angiotensin converting enzyme (ACE) inhibition on tumor necrosis factor-α (TNF-α) and glucose and lipid metabolism parameters. Spontaneously hypertensive rats (SHRs) were fed a fructose-rich diet during 16 weeks of either exercise training (Ex group: 20 m/min, 0% grade, 60 min/day, 5 days/week), administration of an ACE inhibitor (TM group: temocapril, 10 mg/kg/day), or a combination of both (TM+Ex group). The systolic blood pressure was reduced exclusively in the TM and TM+Ex group. Epididymal fat pads (EPI) weighed less in the TM+Ex group than in the single-treatment (TM) group. The serum leptin level was significantly and directly correlated with the EPI weight (p<0.001). The TNF-α content per gram of EPI was the highest in the TM+Ex group. In addition, the EPI TNF-α level was negatively correlated with both the EPI weight and the serum leptin level (p<0.001, respectively). In contrast, the TNF-α level of skeletal muscles was identical among the groups. The extensor digitorum longus had a significantly higher abundance of TNF-α protein than the soleus muscle. These data indicate that the local TNF-α expression is tissue-specific, and that upregulation of TNF-α in EPI by exercise training and/or ACE inhibition may have contributed to the reduction in fat cell volume via the induction of apoptosis and/or the regulation of metabolic homeostasis.