Hepatic uridine-diphosphate glucuronyl transferase activity of guinea pig with scurvy

Ascorbic acid (AsA) concentrations in plasma exert a modulating effect on the activity of liver enzymes. Since UDP-glucuronyl transferase is a liver enzyme, which is responsible for bilirubin glucuronidation, the effect of varied amounts of AsA on this enzyme activity was studied. Sixty male guinea-pigs were randomly allocated to the following six groups: controls, scorbutic and groups given 2, 5, 10 or 20 mg of ascorbic acid, respectively. All the animals with the vitamin C deficient diet presented clinical signs of scurvy at the end of the experimental period, and had lost both body and liver weight compared to all other groups. Scorbutic animals had very low levels of AsA in the liver compared with controls (0.20 +/- 0.10 and 1.65 +/- 0.45 mg/g liver, respectively) (p less than 0.001). Liver AsA levels increased as the AsA dose increased. The UDP-glucuronyl transferase activity was lower in scorbutic animals than in controls (6.20 +/- 1.95 and 23.85 +/- 4.20 mg bilirubin/g protein/h, respectively) (p less than 0.001). The other groups C, D, E and F also had higher mean levels of UDP-GT activity than the scorbutic group B. Finally, no correlation was found between UDP-glucuronyl transferase activity and ascorbic acid intake.