Biliary Excretion of Hexachloro-1,3-butadiene and Its Relevance to Tissue Uptake and Renal Excretion in Rats

The uptake and excretion of carbon-14-labeled hexachloro-1,3-butadiene (HCBD) by rats was monitored in a study of the role of saturation mechanisms involved in urinary HCBD excretion. Rats used in the experiment included bile duct-cannulated and noncannulated animals, in addition to bile duct-duodenum cannula-linked animals. Fractional HCBD urinary excretion among the noncannulated rats decreased with increased chemical dosages, while bile-duct cannulated rats exhibited a constant fractional HCBD urinary excretion level. Measurements were also made of pulmonary and fecal excretion rates, and super( 14)C radioactivity was used to trace the fate of all HCBD. Results suggest hepatobiliary but not renal-excretory saturation.