Excretion, Distribution and Metabolic Fate of Sodium o-Phenylphenate and o-Phenylphenol in the Rat

Abstract

Excretion, organ distribution and metabolic fate of sodium o-phenylphenate (OPP-Na) and o-phenylphenol (OPP) were studied in male rats mainly with 14C-compounds. Both OPP-Na and OPP were rapidly excreted in the urine and feces following oral administration. About 85-90% of the dose appeared in the urine, but only 3-4% in the feces within 48hr. Biliary excretion amounted to about 27% of the dose 72hr after oral administration of OPP-Na, and was higher than that in the feces. This fact suggests that enterohepatic circulation of OPP metabolites occurs in the body. No significant retention was observed in organs and tissues on Days 1, 3 and 7 for OPP-Na, and Days 1 and 7 for OPP after dosing. Autoradiographic studies of intact rats gave the same results. The major metabolites in the urine were the conjugates of OPP after a single oral administration of OPP-Na. OPP, 2, 5-dihydroxydiphenyl (DHD) and 2-phenyl-p-benzoquinone (PBQ) in a free state were identified in the pooled urine of the rats receiving the 2% OPP-Na diets for 2 weeks. No remarkable difference was observed in excretion pattern or metabolites between OPP-Na and OPP in the single dose experiments.