Anthranilic acid metabolism in the isolated perfused rat liver: detection and determination of anthranilic acid and its related substances using high-performance liquid chromatography with electrochemical detection.

In order to elucidate the anthranilic acid metabolism in animal tissue, the metabolism was studied in the isolated perfused liver of rats. A sensitive and rapid method was devised for determination of anthranilic acid and its related substances using high-performance liquid chromatography with electrochemical detection. 5-Hydroxyanthranilic acid and anthranilamide, which have not been detected in animal tissue, were found in the perfusate and in the bile secreted from the perfused liver, respectively. In addition, a non-enzymatic production of anthranilamide from anthraniloyl glucuronide in the presence of ammonium and bicarbonate ions was also observed. These present results suggest that, apart from undergoing glycine or glucuronide conjugation, anthranilic acid is metabolized to 5-hydroxyanthranilic acid and anthranilamide in the rat liver.