虎杖-桂枝药对配伍对大鼠慢性高尿酸血症和肾、肠尿酸转运体表达的影响

目的:研究虎杖-桂枝药对配伍对大鼠高尿酸血症的防治作用及对尿酸盐阴离子转运体1(URAT1),有机阴离子转运蛋白3(OAT3),三磷酸腺苷结合盒转运蛋白2(ABCG2)表达的影响。方法:84只SD雄性大鼠随机分为正常组,模型组,苯溴马隆组(10 mg·kg~(-1)),痛风定组(160 mg·kg~(-1))和虎桂低、中、高剂量组(3.5,7,14 g·kg~(-1))。以皮下注射氧嗪酸钾(200mg·kg~(-1))和ig次黄嘌呤(50 mg·kg~(-1))和乙胺丁醇(250 mg·kg~(-1))的方法,建立高尿酸血症大鼠模型。第4天开始各组大鼠ig给予相应药物,每天1次,连续2周,测定血尿酸(SUA),尿尿酸浓度(UUA),肌酐(Cr),尿素氮(BUN),谷丙转氨酶(GPT)水平;以RT-PCR方法测定大鼠肾脏URAT1和OAT3和小肠ABCG2的mRNA表达水平,以Western blot方法测定大鼠肾脏URAT1和OAT3的蛋白表达水平;以免疫组化方法测定大鼠小肠ABCG2的蛋白表达水平。结果:与正常组比较,模型组大鼠血尿酸水平显著升高,尿尿酸排泄减少,肾脏URAT1 mRNA和蛋白高表达,肾OAT3和小肠ABCG2 mRNA和蛋白低表达,具有明显统计学差异(P0.01)。与模型组比较,虎桂药对高中剂量组能显著降低血尿酸和尿素氮水平,增加24 h尿酸排泄量;虎桂药对高中剂量组能显著降低肾脏URAT1 mRNA和蛋白表达量水平,升高肾脏OAT3和小肠ABCG2 mRNA和蛋白的表达量水平,均具有明显统计学差异(P0.01,P0.05)。结论:虎桂药对有明显的抗高尿酸血症作用,可能是通过下调大鼠肾脏URAT1的表达,并上调大鼠肾脏OAT3和小肠ABCG2的表达而减少尿酸的重吸收并增加其排泄。

Effect of Polygoni Cuspidati Rhizoma et Radix-Cinnamomi Ramulus on Chronic Hyperuricemia and Expressions of Renal and Intestinal Uric Acid Transporters in Rats

Objective:To study the preventive and therapeutic effects of the combination of Polygoni Cuspidati Rhizoma et Radix and Cinnamomi Ramulus(PC) on hyperuricemia, and its effect on urate-anion transporter 1(URAT1), organic anion transporters 3(OAT3) and ATP-bindingcassette subfamily G member 2(ABCG2) in rats. Method:Eighty four male SD rats were randomly divided into 7 groups:the normal group, the model group, the benzbromarone (10 mg·kg^-1) group, the Tongfengding capsule (160 mg·kg^-1) group and PC compatibility low-, medium-and high-dose (3.5,7,14 g·kg^-1) groups, with 10 rats in each group. The hyperuricemia model in rats was established through ip injection of potassium oxonate (200 mg·kg^-1), ig administration of hypoxanthine (50 mg·kg^-1) and ethambutol (250 mg·kg^-1). Since the fourth day, all the rats were intragastrically administered with drugs for 2 weeks, once a day, in order to determine their serum uric acid (SUA), creatinine (Cr), blood urea nitrogen (BUN), glutamic-pyruvic transaminase (GPT), as well as urinary uric acid (UUA) levels. The RT-PCR method was used to measure the mRNA levels of renal URAT1, OAT3 and intestinal ABCG2 in rats. Renal URAT1 and OAT3 protein expressions in rats were determined by Western blotting method. Intestinal ABCG2 protein expression in rats was assayed by immunohistochemistry method. Result:Compared to the normal group, SUA levels of the model group increased significantly and excretion of UUA decreased, with high expressions of renal URAT1 mRNA and protein, low expressions of renal OAT3 and intestinal ABCG2 mRNA and protein expression. The results between the normal group and the model group showed significant statistical differences (P<0.01). Compared to the model group,PC medium-dose and high-dose groups showed significantly reduction in SUA and BUN levels, and increase in 24 h excretion of uric acid. PC medium-dose and high-dose groups showed inhibition in renal URAT1 mRNA and protein levels, and increase in renal OAT3 and intestinal ABCG2 mRNA and protein levels. The results between the two groups showed significant statistical differences (P<0.05, P<0.01). Conclusion:PC has an obvious effect of anti-hyperuricemia. It may down-regulate the expression of renal URAT1 and up-regulate the expressions of renal OAT3 and intestinal ABCG2 in rats to reduce re-absorption of uric acid and increase the excretion of uric acid.