7-Methyl bile acids: 7 beta-methyl-cholic acid inhibits bacterial 7-dehydroxylation of cholic acid and chenodeoxycholic acid in the hamster.
The effect of dietary 7 beta-methyl-cholic acid [0.075% in rodent chow (6.4 mg/animal per day)] on cholesterol and bile acid metabolism was studied and compared with that of cholic acid in the hamster. Following oral administration of 7 beta-methyl-cholic acid for 3 weeks, the glycine-conjugated bile acid analog became a major constituent of gallbladder bile. Biliary cholic acid concentration decreased significantly, while that of chenodeoxycholic acid remained unchanged. Serum and liver cholesterol levels were increased by dietary 7 beta-methyl-cholic acid and by cholic acid. Hepatic microsomal HMG-CoA reductase activity was inhibited (30% of the control value) by both bile acids; cholesterol 7 alpha-hydroxylase activity was not affected. In chow controls and cholic acid-fed animals, bacterial 7-dehydroxylation of [14C]chenodeoxycholic acid and [14C]cholic acid was nearly complete. In contrast, dietary 7 beta-methyl-cholic acid effectively prevented the 7-dehydroxylation of the two primary bile acids. These results show that dietary 7 beta-methyl-cholic acid is preserved in the enterohepatic circulation and has an effect on serum and liver cholesterol concentrations similar to those produced by the naturally occurring cholic acid. 7 beta-Methyl-cholic acid is an efficient inhibitor of the bacterial 7-dehydroxylation of the primary bile acids in the hamster.
D000818:Animals; D001419:Bacteria / Q000187:drug effects / Q000378:metabolism*; D001647:Bile Acids and Salts / Q000378:metabolism; D002635:Chenodeoxycholic Acid / Q000378:metabolism*; D002784:Cholesterol / Q000097:blood; D002790:Cholesterol 7-alpha-Hydroxylase / Q000378:metabolism; D002793:Cholic Acids / Q000378:metabolism* / Q000494:pharmacology*; D006224:Cricetinae; D006904:Hydroxymethylglutaryl-CoA Synthase / Q000378:metabolism; D050356:Lipid Metabolism; D008297:Male; D008647:Mesocricetus; D008862:Microsomes, Liver / Q000201:enzymology / Q000378:metabolism; D051381:Rats; D011919:Rats, Inbred Strains
D001647:Bile Acids and Salts; D002793:Cholic Acids; D002635:Chenodeoxycholic Acid; C051656:3,7,12-trihydroxy-7-methylcholanoic acid; D002784:Cholesterol; D002790:Cholesterol 7-alpha-Hydroxylase; D006904:Hydroxymethylglutaryl-CoA Synthase