DIFFERENCE BETWEEN CHOLIC ACID AND CHENODEOXYCHOLIC ACID IN DEPENDENCE UPON CHOLESTEROL OF HEPATIC AND PLASMATIC SOURCES AS THE PRECURSOR IN RATS

Article abstract of DOI:10.1016/0039-128X(83)90091-0

Some difference in functional pool of cholesterol acting as the precursor of bile acids is pointed out between cholic acid and chenodeoxycholic acid.In order to elucidate this problem further, some experiments were performed with rats equilibrated <7(n)-3H, 4-14C>cholesterol by subcutaneous implantation.The bile duct was cannulated in one series of experiments and ligated in another.After the operation 14C-specific radioactivity of serum cholesterol fell, but reached practically a new equilibrium within three days. 14C-Specific radioactivity of serum cholesterol as well as of biliary bile acids in bile-fistula rats and urinary bile aci ds in bile duct-ligated rats was determined during a three days-period in the new equilibrated state.The results were as follows: (1) 14C-Specific radioactivity of cholic acid and chenodeoxycholic acid in bile was lower than that of serum cholesterol, and 14C-specific radioactivity of cholic acid was clearly lower than that of chenodeoxycholic acid. (2) 14C-Specific radioactivity of cholic acid and β-muricholic acid in urine was lower than that of serum cholesterol, and 14C-specific radioactivity of cholic acid was lower than that of β-muricholic acid. (3) Biliary as well as urinary β-muricholic acid lost tritium label at 7-position entirely during the course of formation from <7(n)-3H, 4-14C>cholesterol.