BILIRUBIN INHIBITION OF 4-METHYLUMBELLIFERONE GLUCURO CONJUGATION IN VITRO BY HUMAN LIVER

The addition of bilirubin to a system containing human liver homogenate, excess of undine diphosphoglucuronic acid and 4-methylumbelliferone produces an inhibition in the glucuro-conjugation of 4-methylumbelliferone. Under these experimental conditions, the result supports the existence of a single enzyme in human liver, which conjugates both substrates: with bilirubin, an ester glucuronide is formed, and with 4-methylumbelliferone, an ethereal one. © 1968.