The effects of glycine (Gly) and taurine (Tau) added to diets at a 5% level on plasma and liver lipid levels, fecal bile acid excretion and liver cholesterol 7α-hydroxylase activity were investigated with rats fed on 10% and 25% casein diets containing cholesterol. The effects of Gly and Tau on the hypercholesterolemia induced by methionine and choline chloride were also investigated. The plasma cholesterol-lowering effect of Gly was stronger than that of Tau in the 10% casein diet, but the effect was reversed in the 25% casein diet. Although the hypercholesterolemia induced by methionine was almost completely prevented by Gly, the effect of Tau was limited. The plasma cholesterol-lowering effect of Gly could not be fully explained by the stimulation of fecal bile acid excretion, whereas the effect of Tau appeared to be associated with the fecal bile acid excretion. The addition of Tau significantly increased the cholesterol 7α-hydroxylase activity in all the experiments, while Gly had no effect except for that from the 25% casein diet. These results indicate that plasma cholesterol-lowering effects of Gly and Tau are elicited through different mechanisms.
Japan Society for Bioscience, Biotechnology, and Agrochemistry