[Effect of starvation and phenobarbital on the activity of liver uroporphyrinogen synthetase]. / Effet du jeûne et du phénobarbital sur l'activité de l'uroporphyrinogène synthétase hépatique.

Liver uroporphyrinogen synthetase activity was measured in 45 mice, divided in three groups. The mice of the 1st group served as controls, those of the 2nd starved for 24 hours, while those of the 3rd were injected intraperitoneally with phenobarbital. The enzymic activity was found significantly (p less than 0.001) lower in the animals of the 2nd group (17.49 +/- 2.25 nmol/g/h) and higher in those of the 3rd (25.82 +/- 3.73 nmol/g/h) as compared to the controls (20.89 +/- 2.11 nmol/g/h). If these effects also exist in the human it could be suggested that starvation may be doubly harmful for the patients with acute intermittent porphyria by aggravating both their enzymic disorders. On the contrary, in the case of phenobarbital its undesired effect on porphyria may be moderated by a simultaneous induction of the uroporphyrinogen synthetase.