title: Effect of excess dietary L-histidine on plasma cholesterol levels in weanling rats.
abstract: Supplementation of a closed formula, cereal based stock diet with excess L-histidine at a 5% or 8% level for 4 days reduced growth and induced hepatomegaly and an increase in plasma cholesterole levels in weanling rats. The enlargement of the liver was in part due to glycogen accumulation; plasma glucose concentration was unchanged. Feeding four different amino acids (L-phenylalanine, L-glutamic acid, glycine and L-tryptophan), at levels which caused reduction of growth comparable to the 5% and 8% L-histidine supplementation, did not effect liver weight or plasma cholesterol levels. L-Threonine added, at a 2% level, to the 8% L-histidine diet did not alleviate any of the histidine effects. Rats fed a diet containing 5% urocanic acid, the first metabolite of the histidine degradative pathway, grew at a normal rate but had higher plasma cholesterol levels compared to rats fed stock diet. When rats fed L-histidine-or urocanic acid-supplemented diets were returned to stock diet, a normal growth rate was resumed immediately and plasma cholesterol levels returned to normal within 6 days. These results suggest that L-histidine and/or urocanic acid induce a hypercholesterolemia which disappears several days after the supplementation ceases.
mesh_terms: D000818:Animals; D001786:Blood Glucose / Q000378:metabolism; D001835:Body Weight / Q000187:drug effects; D002784:Cholesterol / Q000097:blood*; D004305:Dose-Response Relationship, Drug; D006529:Hepatomegaly / Q000139:chemically induced; D006639:Histidine / Q000009:adverse effects*; D006937:Hypercholesterolemia / Q000139:chemically induced; D008112:Liver Glycogen / Q000378:metabolism; D008297:Male; D051381:Rats; D013912:Threonine / Q000494:pharmacology; D014560:Urocanic Acid / Q000494:pharmacology
chemical_list: D001786:Blood Glucose; D008112:Liver Glycogen; D013912:Threonine; D006639:Histidine; D002784:Cholesterol; D014560:Urocanic Acid