Plasma and lipoprotein cholesterol in rats fed L-amino acid-supplemented diets.
The effect of feeding amino acid-supplemented diets on plasma cholesterol concentration and distribution in the lipoproteins was studied on adult rats. A control diet (without any amino acid addition), and experimental diets supplemented with one of the following L-amino acids: lysine (10%), cystine (5%), methionine (1%), tryptophan (10%), valine (5%), and histidine (5%), were given for 2-4 months. Rats fed the lysine-, cystine- and tryptophan-added diets exhibited constant weights throughout the experiment, whereas those fed the other amino acid-added diets showed body weight gains quite similar to control rats. Two amino acids were shown to lower plasma cholesterol concentration: lysine (by 30%) and tryptophan (by 35%); one amino acid increased it: cystine (by 46%). The cholesterol distribution in the lipoproteins was significantly modified, principally when rats ingested cystine-enriched diets: as compared to control rats, the cholesterol concentration in lipoproteins of density between 1.040 and 1.063, and in high density lipoproteins (HDL), was increased by 174 and 58%, respectively.
D000596:Amino Acids / Q000008:administration & dosage* / Q000494:pharmacology; D000818:Animals; D001835:Body Weight / Q000187:drug effects; D002784:Cholesterol / Q000097:blood*; D003553:Cystine / Q000008:administration & dosage; D004032:Diet; D006639:Histidine / Q000008:administration & dosage; D008074:Lipoproteins / Q000032:analysis*; D008075:Lipoproteins, HDL / Q000032:analysis*; D008239:Lysine / Q000008:administration & dosage; D008297:Male; D008715:Methionine / Q000008:administration & dosage; D051381:Rats; D014364:Tryptophan / Q000008:administration & dosage; D014633:Valine / Q000008:administration & dosage
D000596:Amino Acids; D008074:Lipoproteins; D008075:Lipoproteins, HDL; D003553:Cystine; D006639:Histidine; D014364:Tryptophan; D002784:Cholesterol; D008715:Methionine; D014633:Valine; D008239:Lysine