抄録
The effects of modification of the arginine/Iysine ratio of dietary protein on the cholesterol kinetics were studied in male rats. Single amino acids (lysine to soybean protein and arginine to casein) were added to approximate the arginine/Iysine ratio in different proteins. After acclimation to these diets for 30 days, rats were administered intravenous [14C]cholesterol and oral [3H]cholesterol. Analysis of the die-away curve of [14C]cholesterol showed an apparent independence of cholesterol kinetics to the dietary manipulations, but there was a moderate reduction of the size of the slowly exchangeable pool and of the biliary concentration of cholesterol when lysine was added to soybean protein. Addition of amino acids neither influenced cholesterol absorption nor the fecal excretion of the radioactivities from labeled cholesterol. The results indicate that manipulating the arginine/Iysine ratio of dietary protein by adding single amino acids is not necessarily effective in ameliorating cholesterol metabolism in rats, although the arginine addition caused a significant reduction of serum cholesterol and triglyceride.