Influence of different intake of soy protein on serum uric acid and renal function in hyperuricemic rats

To investigate the influence of different intake of soybean-based protein on sesrum uric acid and renal function in hyperuricemic rats. The hyperuricemic rat induced by 5% potassium oxonate were divided into three groups randomly and fed with low (11%), normal (22%) , high (45%) soy protein diet respectively. The rats were followed for six weeks. Serum and urine biochemical parameters including uric acid, creatinine were measured every week. Compared with 22% soy protein group, serum levels of uric acid in 11% soy protein group were significantly lower in the fourth, fifth and sixth week(P <0.05) whereas serum uric acid levels in 45% soy protein group were significantly higher from the second week to the fifth week(P <0.05). Serum creatinine in 11% soy protein group decreased significantly in the sixth week. Increases of serum creatinine in 45% soy protein group were detected in the second and third week. There were no differences in body weight among the three groups at the end of the study. We have not found any differences in the serum lipid and albumin level, or the amount of urinary excretion of uric acid, creatinine and protein among three groups. In conclusion,high soy-based protein food increased the serum uric acid level and damaged the kidney function in SD rat. However, low soy protein food can maintain the nutritious status in the experienced rats. It also can decrease the serum uric acid level and protect renal function in hyperuricemic rats.