The Effect Of Different Contents Of Soy Protein In Diet On Uric Acid And Renal Function In Hyperuricemic Rats

Objectives:To study the hyperuricemic rat models induced by different Modeling methods and assess the effect of different concentration of soybean-based protein on uric acid and renal function in hyperuricemic rats.Materials and methods:Part 1:The Rats were divided into normal group and three model groups randomly. The standard feed was given as a positive control; the model groups were fed with the 5% Oxonic aicd potassium salt(OA),10% Yeast Extract (YE) or 10% YE +2% OA respectively for three weeks then transfered to standard feed for one week, Serum and urine levels of uric acid and creatinine,and urea nitrogen,and albumin were measured every week.Part 2:The hyperuricemic rats were randomly assigned to four diets:Low soy protein(LSP), Normal soy protein(NSP), High soy protein(HSP) or Normal soy protein and allopurinol (NSP+AP) for a six-week experiment. Serum and urine levels of uric acid and creatinine,and urea nitrogen,and albumin were measured every week.Results:Part 1:1. Compared with control group, the serum uric acid of the rats which fed with 5% OA was significantly higher in the entire experiment (P<0.05).The serum uric acid of the rats which fed with 10%YE was only increased in the second week (P<0.05).In the group fed with 10% YE+2% OA, the serum uric acid of the rats was increased at the first week and the second week (P<0.05) and then decreased.2. The serum creatinine, the serum urea nitrogen, the serum albumin, and the body weight were no significant differences among the four groups.Part 2: 1. Compared with NSP, serum levels of uric acid in LSP and NSP+AP were significantly lower in the fourth, fifth and sixth week(P<0.05), whereas serum uric acid levels in HSP group were significantly higher from the second week to the fifth week(P<0.05). There were no differences in serum uric acid between 11% soy protein group and 22% soy protein with 150mg/L Allopurinol in water group.2. Compared with NSP, serum levels of creatinine in LSP decreased significantly in the sixth week, and serum urea nitrogen decreased in the second,third, fourth and sixth week. Increases of serum creatinine and serum urea nitrogen in HSP were detected in the second and third week.3. Compared with NSP, serum triglyceride in HSP was increased.4. There were no differences in body weight among the four groups at the end of the study. We have not found any differences in the serum cholesterol and albumin level, or the amount of urinary excretion of uric acid, creatinine and protein among four groups.Conclusions:Part 1:1. The hyperuricemic rat model induced by 5% OA was stable and enduring.2.5% OA neither damage to renal function nor increase the incidence of malnutrition in hyperuricemic rats.Part 2:1. LSP significantly decreased the serum uric acid level of hyperuricemic rats and protected renal function. HSP increased serum uric acid in hyperuricemic rats and damaged renal function.2. HSP increased serum triglyceride levels in Hyperuricemia rats.3. LSP couldn't increase the incidence of malnutrition in hyperuricemic rats.