Study On Effect Of Xufu Zhuyu Decoction On The OAT3and The URAT1in The Renal Tubular Epithelial Cells Of Hyperuricemia Rats

Objective:To preliminarily explore the mechanism of Xuefu Zhuyu Decoction (XFZYD) promoting renal excretion of uric acid by observing the effect of XFZYD changing the OAT3and the URATl in the renal tubular epithelial cells of hyperuricemia rats.Methods:Fifty male Sprague-Dauley rats(2001±10g), Specific pathogen Free degree, were randomly divided into five groups:normal group, model group, low dose(0.31g/kg), middle dose(0.62g/kg) and high dose(1.24g/kg) of XFZYD groups. There were ten rats in each group. Except normal group which given the same amount of distilled water by gavage, the other four groups were induced to hyperuricemia models by adenine (100mg/kg) and ethambutol hydrochloride (250mg/kg) in the morning, and in the afternoon, model group were feed with distilled water by gavage while XFZYD groups were feed with different concentrations of XFZYD according to the weight of10ml/kg. Through2weeks of experiment, the rats were intraperitoneally injected with urethan to anesthetize. After abdominal aortic blood collection, excised the left kidney rapidly. Detected the levels of serum UA, Scr and BUN. The pathomorphism changes of renal tissue structure were observed by light microscopy. The expression of OAT3and URAT1protein in the renal tubular epithelial cells were detected by immunohistochemical assay. Real-time PCR assay was used to detect the expression level of OAT3-mRNA and URAT1-mRNA.Results:1. Serum biochemical indicator detection showed:the levels of UA, Scr and BUN in model group and each dose of XFZYD groups were higher than in normal group(P<0.05or P<0.01), in middle dose and high dose of XFZYD groups were lower than in model group(P<0.05or P<0.01).2. Kidney pathological morphological changes:Renal tissue of model group rats manifested a large number of expanded, there were uric acid crystallizations in the renal tubular lumen, a large number of inflammatory cells infiltrated in the renal interstitial, degeneration and necrosis of proximal convoluted tubule epithelial cell. In the middle dose and high dose of XFZYD groups, expansion of the kidney tubules is not obvious, uric acid crystallizations were seen occasionally in the renal tubular lumen, a little inflammatory cells infiltrated in the renal interstitial.3. Immunohistochemical detection showed that the positive target area(PDA) and IOD of OAT3in model group and each dose of XFZYD groups were lower than normal group(P<0.05or P<0.01), PDA and IOD of OAT3in middle dose and high dose of XFZYD groups were higher than model group(P<0.05or P<0.01). PDA and IOD of URAT1in model group and each dose of XFZYD groups were higher than normal group(P<0.05or P<0.01), PDA and IOD of URAT1in middle dose and high dose of XFZYD groups were lower than model group(P<0.05or P<0.01).4. Real-Time PCR assay showed:The relative expression level of OAT3-mRNA in model group and each dose of XFZYD groups were significantly lower than in normal group(2-ΔΔCt <0.5), in middle dose and high dose of XFZYD groups were higher than in model group(2-ΔΔCt>2). The relative expression level of URAT1-mRNA in model group was significantly higher than in normal group(2-ΔΔCt>2), in middle dose and high dose of XFZYD groups were lower than in model group(2-ΔΔCt<0.5).Conclusions:1. XFZYD can reduce the levels of UA, Scr and BUN of hyperuricemia rats, improve the kidney function.2. XFZYD can improve kidney pathological morphology, protect and repair the nephron, alleviate the impairment of renal tubules and renal interstitial, and restrain the progression of inflammation.3. XFZYD can up-regulate the expression of OAT3and down-regulate the expression of URAT1in order to reduce the level of serum uric acid by promoting excretion of uric acid.