PP.19.20

Abstract

Objective: Dietary sugar and fat contribute to adiposity and are deleterious to cardiovascular heath. In addition, high dietary fructose in the absence of dietary fat induces leptin resistance and exacerbates subsequent HF-induced obesity. In addition, augmented leptin is associated with arterial stiffness. Thus, we hypothesized that a high-fat/high-fructose (HF/F) diet would have more severe consequences than a high-fat (HF) or chow diet on cardiovascular health. Design and method: Male Sprague Dawley rats were fed either with chow, HF (30%) or HF/F (30%/44%) diets for 12 weeks (N = 8-10/group) and adiposity, basilar artery reactivity, basilar artery wall thickness, heart weight, and biochemical parameters assessed. Basilar artery was cannulated in a pressurized system (90 cm H2O). Results: Vascular contractile responses to KCl (30-120 mM) were unchanged whereas both HF and HF/F diets decreased relaxation responses to papaverin (10-10-10-4 M, direct smooth muscle); acetylcholine (ACh) (10-10-10-4 M, endothelium dependent); and diethylamine (DEA)-NONO-ate (10-10-10-4 M, endothelium independent) relaxation compared to chow. The log EC50 values were -5.84, chow; -4.87, HF; -4.98, HF/F, p < .05 for papaverin; -6.48, chow; -5.65, HF; 5.79HF/F, p < 0.05 for Ach) and -5.94, chow; -4.45, HF; -4.49, HF/F, p < .05 for DEA. Artery wall thickness was increased only in HF group (27 ± 1.6 μm) compared with chow (22 ± 1.2, p < .05) and eNOS immunofluroescence was decreased by 50% in HF and HF/F diets (arbitrary units, p < .05). Adipose tissue weights (10.7 ± .5 HF; 12.7 ± .8 HF/F vs 7.8 ± .3 chow, p < .05) and total adiposity by TDNMR were elevated by the same degree in both HF and HF/F diets. Blood triglycerides (157 ± 32 mg/dl) and leptin (10.4 ± 1.8ng/ml) were greater with HF/F diet than with HF (65 ± 15; 6.6 ± .6) or chow diet (63 ± 14; 4.1 ± .3). Conclusions: In conclusion, both HF diets impaired basilar artery relaxation, and increased heart weight potentially due to decreased eNOS synthesis. Although, leptin and triglycerides were greater with HF/F diet only the HF increased wall thickness. These data suggest that the presence of high fructose in a HF diet does not exacerbate the detrimental consequences of a HF diet on cardiovascular health.