ENZYMATIC STUDIES IN A CASE OF HEREDITARY TYROSINEMIA WITH HEPATOMA

The activity of δ‐aminolevulinic acid synthetase has been measured in liver and hepatoma tissue from a case of hereditary tyrosinemia with an increased excretion of δ‐aminolevulinic acid in the urine. The enzyme activity in the hepatoma tissue was seven times higher than in the surrounding liver, where the activity was not increased above the reported normal range. The activity of p‐hydroxyphe‐nylpyruvate hydroxylase (EC 1.14.2.2.) was about 25 % of the normal in the liver tissue but not measurable in the hepatoma. Tyrosine aminotransferase (EC 2.6.1.5.) activity was normal in the liver tissue but was not detectable in the hepatoma, whereas the activity of phenylpy‐ruvate keto‐enol isomerase (EC 5.3.2.1.) was the same in liver and hepatoma tissue. Copyright © 1969, Wiley Blackwell. All rights reserved