[The relationship between zinc levels in blood and the activity of delta-amino-levulinic acid dehydratase in human erythrocytes (author's transl)].

The blood levels of zinc, lead, copper and albumin and the activity of erythrocyte delta-aminolevulinic acid dehydratase (ALA D), with and without addition of zinc in vitro, were measured in healthy subjects and in patients with cirrhosis. In cirrhosis there was a decrease, of zinc (-40%) albumin (-38%) and of activity of ALA D (-48%) and an increase in blood lead (+80%). Correlation between these results has been studied. The increase of blood lead is probably the result of zinc decrease. Moreover, as the urinary excretion of zinc is enhanced by chelation therapy, the prescription of zinc in lead intoxication is to be recommended. The activity of ALA D in patients with cirrhosis is less enhanced by addition of zinc in vitro than is the activity in patients intoxicated with lead. Probably in cirrhosis there is especially a decrease in the synthesis of ALA D, and lead intoxication the enzyme is inhibited.