Abstract: Objective To observe the effect of losartan potassium on the expression of Uric acid transporter1(URAT1) in renal epithelial cells of hyperuricemia rats with renal interstitial fibrosis. Methods The rats were randomly divided intonormal group,model group(it was administrated with adenine 100 mg/(kg?d) and Ethambutol 250 mg/(kg?d) by gastric gavage)，losartan potassium low ,in and high (25、50 and75 mg/kg?d) dose treatment group.Serum uric acid, serum creatinine, urea nitrogen, urinary uric acid, urinary creatinine and uric acid excretion fraction were detected at 1, 2, 3and 4W after modeling. Pathological changes of uric acid renal fibrosis rats were observed by HE and Masson staining methods,and the protein expression of URAT-1 was detected in renal tubular epithelial cells by Western blot. Results With the extension of time, serum uric acid level of model group was significantly higher than that of normal group(P<0.01), uric acid level was lower than normal group(P<0.01), serum uric acid level decreased and uric acid level increased in the treatment group, The high dose group was the most obvious(P<0.05).The tubulointerstitial injury index in the model group was significantly higher than that in the normal group (P<0.05), and the tubulointerstitial injury index was significantly decreased after losartan potassium intervention (P<0.05) . The expression of URAT1 protein were up-regulated in the model group at each time period (P<0.05), and with the progress of pathological damage showed an upward trend, but decreased significantly in losartan potassium intervention groups(P<0.05). Conclusions　 Losartan potassium may reduce the high expression of URAT1 and significantly reduce the level of serum uric acid in hyperuricemia rats.

Key words: hyperuricemia, Uric acid renal fibrosis, URAT1, losartan potassium