Effects of whey protein, casein, soya-bean and sunflower proteins on the serum, tissue and faecal steroids in rats.
Four groups of rats were fed for 49 d on one of four semi-purified diets, without added cholesterol and containing 230 g/kg of the following isolated proteins: casein, whey, soya-bean or sunflower. Whey, soya-bean and sunflower proteins, when compared with casein, decreased the level of serum high-density-lipoprotein (HDL)-cholesterol. These low cholesterol levels were accompanied by an increase in the daily faecal excretion of neutral sterols and bile acids in the case of soya-bean protein, and by a decrease in the liver cholesterol content, when rats were fed on whey protein. Considering the amino acid composition of the four purified proteins, we observed that serum total and HDL-cholesterol levels had a significant positive correlation with tyrosine and glutamic acid, and a negative correlation with cystine and alanine. The present study showed that the hypocholesterolaemic effect of dietary proteins was not related to their animal or vegetable origin.
D000818:Animals; D001011:Aorta / Q000378:metabolism; D002364:Caseins / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood / Q000378:metabolism*; D008076:Cholesterol, HDL; D004044:Dietary Proteins / Q000494:pharmacology*; D005243:Feces / Q000032:analysis; D007785:Lactose; D008075:Lipoproteins, HDL / Q000097:blood; D008099:Liver / Q000378:metabolism; D008297:Male; D008894:Milk Proteins / Q000494:pharmacology; D010940:Plant Proteins / Q000494:pharmacology; D051381:Rats; D011919:Rats, Inbred Strains; D013025:Glycine max; D013261:Sterols / Q000032:analysis; D014280:Triglycerides / Q000097:blood
D002364:Caseins; D008076:Cholesterol, HDL; D004044:Dietary Proteins; D008075:Lipoproteins, HDL; D008894:Milk Proteins; D010940:Plant Proteins; D013261:Sterols; D014280:Triglycerides; D002784:Cholesterol; D007785:Lactose