Effects of dietary protein and amino acids on the metabolism of cholesterol-carrying lipoproteins in rats.
The effect of various dietary proteins and amino acids on serum lipid metabolism was studied by using male Sprague-Dawley rats. A stock diet containing casein as a protein source was fed to control animals, whereas a vegetable protein diet (cottonseed based) was fed to one experimental group. Two other experimental diets were formulated to determine if the amino acid ratios in the protein played a role in the alteration of serum cholesterol levels. One of these diets contained casein plus enough additional arginine to make its arginine-to-lysine ratio similar to that found in cottonseed protein. The other diet contained cottonseed protein plus enough lysine to duplicate the arginine-to-lysine ratio of casein. Rats fed a diet containing protein from animal sources had greater serum and high-density lipoprotein (HDL)-cholesterol concentrations as well as increased lecithin: cholesterol acyltransferase (LCAT, EC 2.3.1.43) activities than those which had been fed a diet containing protein from plant sources. Animals fed arginine-supplemented casein diet showed a decrease in both serum and HDL-cholesterol when compared to the casein control group, whereas the addition of lysine to cottonseed protein diet caused an increase in the same two cholesterol fractions.
D000596:Amino Acids / Q000494:pharmacology*; D000818:Animals; D000924:Anticholesteremic Agents; D001120:Arginine / Q000494:pharmacology; D002364:Caseins / Q000494:pharmacology; D002784:Cholesterol / Q000097:blood*; D008076:Cholesterol, HDL; D004044:Dietary Proteins / Q000494:pharmacology*; D003368:Gossypium; D008074:Lipoproteins / Q000097:blood*; D008075:Lipoproteins, HDL / Q000097:blood; D008239:Lysine / Q000494:pharmacology; D008297:Male; D007862:Phosphatidylcholine-Sterol O-Acyltransferase / Q000097:blood; D010940:Plant Proteins / Q000494:pharmacology*; D051381:Rats; D011919:Rats, Inbred Strains; D012639:Seeds
D000596:Amino Acids; D000924:Anticholesteremic Agents; D002364:Caseins; D008076:Cholesterol, HDL; D004044:Dietary Proteins; D008074:Lipoproteins; D008075:Lipoproteins, HDL; D010940:Plant Proteins; C030104:lipoprotein cholesterol; D001120:Arginine; D002784:Cholesterol; D007862:Phosphatidylcholine-Sterol O-Acyltransferase; D008239:Lysine