Aliskiren prevents and ameliorates metabolic syndrome in fructose-fed rats

Introduction: The renin-angiotensin system plays a major role in the pathogenesis of metabolic syndrome. The objective of this study was to examine the effects of aliskiren, a direct renin inhibitor, on the metabolic syndrome of fructose-fed rats. Material and methods: Male Sprague-Dawley rats were divided into 4 groups (n = 6 for each group). Group Con: rats were fed a standard chow diet for 8 weeks, group Fru: rats were fed a high fructose diet (60% fructose) for 8 weeks, group FruA: rats were fed a high fructose diet and were co-infused with aliskiren (100 mg/kg/day), and group FruB: rats were treated as group Fru, but aliskiren was administered 4 weeks later. Systolic blood pressure (SBP), homeostasis model assessment-insulin resistance (HOMA-IR), and blood profiles were measured. Results: By the end of week 4 and 8 of a high fructose diet, SBP had increased significantly from 111 +/- 5 to 142 +/- 4 and 139 +/- 5 mmHg (p < 0.05), respectively. A high fructose diet significantly increased HOMA-IR from baseline (6.15 +/- 1.59) to 21.25 +/- 2.08 and 21.28 +/- 3.1 (p < 0.05) at week 4 and 8, respectively, and significantly induced metabolic syndrome. Concurrent aliskiren treatment prevented the development of hypertension and metabolic syndrome in fructose-fed rats. When fructose-induced hypertension was established, subsequent aliskiren treatment for 4 weeks reversed the elevated SBP and ameliorated metabolic syndrome. There were no significant differences in food, water intake, urine flow or body weight gain among groups. Conclusions: Aliskiren not only prevents but also ameliorates metabolic syndrome in fructose-fed rats.