Enzymatic Defect in Metabolism of Bilirubin in Fetal and Newborn Rat

Abstract

Summary1. Homogenate preparations of liver and kidney from fetal rats failed to synthesize bilirubin glucuronides. The conjugative activity did not reach normal levels until the animal was 5 to 6 weeks old. 2. The levels of uridine diphosphoglucuronic acid were only 10% of those found in adult tissue. 3. Inhibition of beta glucuronidase with potassium saccharate did not stimulate the conjugation of bilirubin. Phenolphthalein glucuronide was not hydrolyzed. 4. No conjugation was observed in homogenates of stomach, intestine or placental tissue. 5. The evidence presented suggests that glucuronyl transferase activity and the production of uridine diphosphoglucuronic acid are impaired in the newborn and the premature animal.