Quercetin Protects against Cadmium-Induced Renal Uric Acid Transport System Alteration and Lipid Metabolism Disorder in Rats

Hyperuricemia and dyslipidemia are involved in Cd nephrotoxicity. The aim of this study was to determine the effect of quercetin, a dietary flavonoid with anti-hyperuricemic and anti-dyslipidemic properties, on the alteration of renal UA transport system and disorder of renal lipid accumulation in 3 and 6 mg/kg Cd-exposed rats for 4 weeks. Cd exposure induced hyperuricemia with renal XOR hyperactivity and UA excretion dysfunction in rats. Simultaneously, abnormal expression levels of renal UA transport-related proteins including RST, OAT1, MRP4 and ABCG2 were observed in Cd-exposed rats with inhibitory activity of renal Na(+)-K(+)-ATPase. Furthermore, Cd exposure disturbed lipid metabolism with down-regulation of AMPK and its downstream targets PPARα, OCTN2 and CPT1 expressions, and up-regulation of PGC-1β and SREBP-1 expressions in renal cortex of rats. We had proved that Cd-induced disorder of renal UA transport and production system might have cross-talking with renal AMPK-PPARα/PGC-1β signal pathway impairment, contributing to Cd nephrotoxicity of rats. Quercetin was found to be effective against Cd-induced dysexpression of RST and OAT1 with XOR hyperactivity and impairment of AMPK-PPARα/PGC-1β signal pathway, resulting in renal lipid accumulation reduction of rats.