Objective   To invstigate the effects of dietary soybean peptides intake on the concentration of serum total cholesterol(TC)and serum lipids in hyper cholesterolemic rats and to study the mechaisms.

  Methods   Following 28 days of inducing the hypercholesterolemia model successfully, rats were fed a purified diet containing either casein or soy bean peptides.After the rats were fed experimental diets for 56 days, fasting animals were killed.

  Results   In the end of the experiment, TC was(6.41±0.57)and(3.01±0.37)mmol/L in the rats fed diets containing casein and soybean peptides, respectively.Triglyceride(TG)was(3.73±0.70)and(1.09±0.34)mmol/L, respectively.Serum apolipoprotein B(apoB)was (0.62±0.11)and(0.31±0.07)g/L, respectively.Accordingly, FT4 was(1.03±0.22)and(1.76±0.30)pmol/L, respectively.Comparing with the rats in casein group, the TC, TG and apoB in soybean peptides group were significantly low (P < 0.05).The concentration of FT4 was higher in the rats of soybean peptides group(P < 0.05).Whereas, the changes of HDL-C, apoA, FT3, TSH and insulin(INS)were not significant in these rats.

  Conclusion   Dietary soybean peptides intake may lower TC by changing the concentrations of apoB and FT4.Further researches were needed for explaining the possible mechanism of soybean peptides intake on lowing TC.