Serum lipids of rats fed excess L-lysine and different carbohydrates
Hevia, P.; Ulman, E.A.; Kari, F.W.; Visek, W.J.
Journal of Nutrition 110(6): 1231-1239
1980
ISSN/ISBN: 0022-3166 PMID: 6770060 Document Number: 157651
Liver and serum lipids were compared in male weanling rats fed for 14 days on a diet with 15% casein plus 5% lysine, threonine, valine or glutamic acid. Lysine increased liver total lipids, triglycerides and cholesterol by 200, 600 and 200%, respectively, without affecting serum lipids. Threonine and valine also increased liver triglycerides but only by about 200%. Feeding on valine was associated with hypertriglyceridaemia whereas the diet with arginine and glutamic acid produced slight hypercholesterolaemia. Adding 1% methionine or arginine prevented the fatty liver with 5% lysine. Only liver triglycerides, the lipid class showing the greatest increases with lysine diet, were reduced significantly by methionine, whereas arginine reduced all lipid classes nearly to control values. Methionine 1% increased serum lipids, triglycerides, cholesterol and phospholipids by 50, 30, 10 and 30%, respectively. Replacement of sucrose by dextrin-sucrose reduced the liver lipid accumulation with 5% lysine slightly; 7.5% cellulose in the sucrose diet increased it. Neither glucose nor fructose affected the liver lipid accumulation with 5% lysine but glucose with lysine reduced serum lipids. Rats on 5% lysine for 6 weeks had no fatty livers.