Comparison of absorption and metabolism of beta-sitosterol and beta-sitostanol in rats.
The fates of [4-14C]beta-sitosterol ([14C]S) and [4-14C]beta-sitostanol ([14C]HS) were compared after after oral or intravenous administration to rats. Excretion into feces of oral [14C]HS was significantly higher than that of [14C]S. More than 97% of [14C]HS and 88% of [14CS]S were recovered in the feces within 7 days. Thus, deposition of [14C]HS was negligible in the tissues that were examined. Turnover in serum of [14C]HS which was injected intravenously appeared to be more rapid than that of [14C]S; [14C]HS was excreted as neutral steroids at a rate more than twice that of [14C]S. The rate of excretion of [3H]cholesterol was slightly greater when HS was administered simultaneously. The liver contained significantly less radioactivity after [14C]HS than after [14C]S administration. More [14C]HS than [14C]S was present in esterified form in serum and liver. The ratio of sterol in very low density lipoprotein to that in high density lipoprotein was less for HS or S than for endogenous cholesterol; this was particularly marked with HS. These results suggest that HS would be a more effective hypocholesterolemic agent than S.
D000284:Administration, Oral; D000818:Animals; D001647:Bile Acids and Salts / Q000378:metabolism; D002784:Cholesterol / Q000097:blood; D002788:Cholesterol Esters / Q000097:blood; D005243:Feces / Q000032:analysis; D007263:Infusions, Parenteral; D007408:Intestinal Absorption; D008074:Lipoproteins / Q000097:blood; D008099:Liver / Q000378:metabolism; D008297:Male; D008657:Metabolic Clearance Rate; D051381:Rats; D012855:Sitosterols / Q000378:metabolism*; D013256:Steroids / Q000378:metabolism; D014018:Tissue Distribution
D001647:Bile Acids and Salts; D002788:Cholesterol Esters; D008074:Lipoproteins; D012855:Sitosterols; D013256:Steroids; D002784:Cholesterol