Factors affecting the excretion of 14C-dicumarol in the bile of rats.

1. After i.v. injection of equivalent doses of 14C-dicumarol, male rats excreted about 2 1/2 times more radioactivity in bile (9.3 +/- 0.7% in 2 hr) than did females (3.9 +/- 0.4% in 2 hr). 2. Exogenous agents: while 24 hr pretreatment with benzpyrene or 3-methylcholanthrene did not alter the excretion of 14C-dicumarol and its metabolities in bile, pretreatment with carbon tetrachloride reduced radioactivity in the bile of male rats 60%. Following single rapid injection of sulfobromphthalein (BSP), the radioactivity in bile, decreased 70%. 3. Most of the radioactivity in bile (80-90%) was present in metabolized form regardless of the dose, the sex of the rat, or the exogenous agent used.