CARDIOMETABOLIC EFFECTS OF HIGH-FRUCTOSE INTAKE IN NORMOTENSIVE AND HYPERTENSIVE RATS

The aim of this study was to analyze the magnitude of cardiovascular and metabolic impairment due to high-fructose treatment in adult normotensive Wistar and spontaneously hypertensive rats (SHR). Rats of each strain were divided randomly into two groups: control group drinking just tap water, and a group given water containing 10% fructose. Systolic blood pressure was measured weekly by tail-cuff method. After 8 weeks of treatment, rats were sacrificed and relative heart and liver weight was determined. Plasma concentrations of triglycerides, total cholesterol and glucose were measured. Rings of isolated thoracic aorta were suspended in organ baths containing modified Krebs solution and connected to a force-displacement transducer for the recording of isometric tension. We found that fructose feeding induced elevation of blood pressure in SHR as well as in normotensive Wistar rats; however, weight gain was significant only in SHR. In both rat strains, this treatment resulted in increase of relative liver weight and plasma concentration of glucose and triglycerides; total cholesterol in plasma was elevated only in SHR. Endothelium-dependent relaxations of thoracic aorta were impaired in all fructose-fed rats. Moreover, contractile responses to noradrenaline were diminished in aortic rings from fructose-fed SHR, but not in that from Wistar rats. These results suggest that the incidence and intensity of fructose-induced abnormalities is higher in rats with previous cardiovascular impairment due to genetic hypertension.