Impact of high fat/high salt diet on myocardial oxidative stress

Background: High fat high salt diet contributes to oxidative stress and cardiac diseases. Aims: To determine the impact of moderately high fat diet (HFD), high salt (HS) or their combination on blood pressure (Bp) and myocardial oxidants/antioxidants. Methods: Sprague Dawley rats were assigned into four groups; conventional diet (control, 5% fat, 0.5% NaCl), HFD (25% fat, 0.5% NaCl), HS (5% fat, 8% NaCl), or combined diet (HFD+HS) for 10 weeks. Bp and cardiac oxidants and antioxidants were measured. Result: HFD, HS, and their combination didn’t cause obesity or dyslipidemia. Both HS and combined diets resulted in an increase in the heart/body weight ratio accompanied by an increase in Bp. No changes were observed in levels of the glutathione (GSH) system or superoxide dismutase (SOD) activities. However, a significant decrease in TBARS levels was observed in the HFD and the combined diet with a parallel increase in catalase activity in all groups. Relative to HFD, the combined diet was associated with increases in GSH reductase/peroxidase and SOD activities. Conclusions: The lack of changes in the GSH system, the decrease in TBARS, and the increase in catalase activity suggest that normal hearts adapt compensatory mechanisms to prevent oxidative damage in response to HFD/and or HS.