Background/aims: The effect of febuxostat (Fx), a non-purine and selective xanthine oxidase inhibitor, on glomerular microcirculatory changes in 5/6 nephrectomy (5/6 Nx) Wistar rats with and without oxonic acid (OA)-induced hyperuricemia was evaluated.
Methods: Four groups were studied: 5/6 Nx+vehicle (V)+placebo (P) (n = 7); 5/6 Nx+V+Fx (n = 8); 5/6 Nx+OA+P (n = 6) and 5/6 Nx+OA+Fx (n = 10). OA (750 mg/kg/day, oral gavage) and Fx (3-4 mg/kg/day, drinking water) were administered for 4 weeks. Systolic blood pressure, proteinuria and plasma uric acid were measured at baseline and at the end of 4 weeks. Measurement of glomerular hemodynamics and evaluation of histology were performed at the end of 4 weeks.
Results: 5/6 Nx+OA+P rats developed hyperuricemia, renal vasoconstriction and glomerular hypertension in association with further aggravation of afferent arteriolopathy compared to 5/6 Nx+V+P. Fx prevented hyperuricemia in 5/6 Nx+OA+Fx rats and ameliorated proteinuria, preserved renal function and prevented glomerular hypertension in both 5/6 Nx+V+Fx and 5/6 Nx+OA+Fx groups. Functional improvement was accompanied by preservation of afferent arteriolar morphology and reduced tubulointerstitial fibrosis.
Conclusion: Fx prevented renal injury in 5/6 Nx rats with and without coexisting hyperuricemia. Because Fx helped to preserve preglomerular vessel morphology, normal glomerular pressure was maintained even in the presence of systemic hypertension.
Copyright 2008 S. Karger AG, Basel.