RESUMO
The biliary and urinary excretion of tyropanoate-derived material was studied in the anesthetized dog with various plasma levels of tyropanoate. Bile, plasma, urine, and hepatic tissue were analyzed by high-pressure liquid chromatography for the presence of tyropanoate, enantiomers of tyropanoate glucuronide, and other typropanoate metabolites. Approximately 90% of the material secreted in the bile was in the form of tyropanoate glucuronide, equally distributed between (+)- and(-)-tyropanoate glucuronide, and approximately 10% was excreted as other tyropanoate-derived metabolites. It is suggested that the choleretic effect associated with the excretion of tyropanoate is associated with the nonglucuronide metabolites. Tyropanoate itself was not secreted into bile. In plasma, approximately 40% of the material was tyropanoate, while approximately 50% existed as tyropanoate glucuronide and 10% as other tyropanoate metabolites. The plasma concentration of (-)-tyropanoate glucuronide was significantly greater than that of (+)-tyropanoate glucuronide. The urinary excretion of tyropanoate-derived material accounted for up to 35% of the total excretion. The primary metabolite in urine was tyropanoate glucuronide. Tyropanoate accounted for less than 5% of the material in urine, whereas other tyropanoate metabolites contributed approximately 20%. The data suggest that there is a stereoselective disposition of tyropanoate metabolites that may influence the overall disposition of the compound.