Metabolism of [14C]phenol by sheep, pig and rat

1. Following an oral dose of [14C]phenol (12.5 or 25 mg/kg) to sheep, pig and rat, urinary elimination of radioactivity was rapid, 80-90% dose being excreted in the first 8 h. 2. In anaesthetized, ureter-cannulated rats, 70-80% of an intraduodenal dose was eliminated in 2 h; 2% dose was excreted as phenol conjugates in the urine within 10 min. 3. The major urinary metabolites from phenol (25 mg/kg) were phenylglucuronide and phenylsulphate. In the sheep, pig and rat, the glucuronide accounted for 49%, 83% and 42% respectively, of the total urinary metabolites and sulphate accounted for 32%, 1% and 55%. Conjugates of quinol were minor urinary metabolites (less than 7%) in all three species. 4. In sheep some 12% of the urinary metabolites was conjugated with phosphate; this metabolite was not found in rat or pig.