Abstract P185: Cardiometabolic and Inflammatory Biomarkers in the Dahl Salt-sensitive Rat

Abstract

The Dahl salt-sensitive (Dahl/SS) rat is a genetic model of salt-sensitive hypertension that develops left ventricle (LV) hypertrophy after five to six weeks and cardiac failure with LV dilation and contractile dysfunction after 10 to 12 weeks of high-salt intake. The aim of the present study was to evalute cardiometabolic and inflammatory biomarkers in the Dahl/SS rat fed a normal-salt diet (NS-0.3% NaCl) and a high-salt diet (HS-8% NaCl). For that purpose, eight week-old Dahl/SS rats were randomized into two groups, one group received a HS and the other a NS diet for 10 weeks. In the last week of treatment, 3 out of 10 animals from the HS diet group died. All animals from the NS diet group survived (n=8). The high-salt diet induced heart and kidney hypertrophy, as shown by higher heart/body weight (3.86±0.05 vs 2.96±0.05 mg/g, p<0.05) and kidney/body weight ratios (5.23±0.29 vs 3.41±0.06 mg/g, p<0.05), as compared to the NS diet group counterparts. Rats in the HS diet group presented proteinuria (273.1±26.8 vs 34.5±2.6 mg/day, p<0.05), hypercholesterolemia (4.45±0.23 vs 3.07±0.22 mmol/l, p<0.05), reduced levels of free fatty acids (0.23±0.02 vs 0.35±0.02 mmol/l, p<0.05) and normal levels of triglycerides in plasma (1.87±0.29 vs 1.28±0.15 mmol/l, p>0.05), as compared to animals on a NS diet. Insulin plasma levels in the HS group were lower than in the NS group (1.82±0.13 vs 4.03±0.40 ng/ml, p<0.05), though the glucose plasma levels were unchanged (162±5 vs 150±7 mg/dl, p>0.05). The plasma levels of monocyte chemoattractant protein (MCP)-1 were higher in the HS than in LS diet group (105.0±10.4 vs 67.6±2.8 pg/ml, p<0.05). A multiplex inflammatory cytokine assay was used to profile expression of 23 inflammatory mediators. The plasma levels of nine inflammatory mediators, including IL-1β, IL-4 and VEGF, were significantly increased in rats in the HS group. In conclusion, HS diet feeding in the Dahl/SS rat deteriorate cardiometabolic and inflammatory biomarkers.