1989 年 4 巻 6 号 p. 743-753
The metabolites of beraprost sodium in plasma and tissues, and its biliary excretion and enterohepatic circulation were investigated in male and female rats using 3H-labelled substance.
The most predominant metabolite, 2, 3-dinor-beraprost was shown to be distributed mainly in the liver. However, this β-oxidation metabolite was found to be produced in male rats at an apparently higher level than in female rats. On the other hand, as the oxidation of C-15 alcohol is concerned, the females possess higher capacity for this biotransformation process. The study on biliary excretion showed that male rats could excrete more drug, principally as 2, 3-dinor-beraprost, into the bile compared to the female rats. This sex difference in biliary excretion was facilitated by the following enterohepatic circulation. As a result, urinary excretion of beraprost sodium in female rats attained nearly four times of that in male rats.
All these results seem to be basically related to the difference in β-oxidation capacity in the liver of both sexes.
