New Method for Determination of Aminolaevulinate Dehydratase Activity of Human Erythrocytes as an Index of Lead Exposure

[摘要] I describe a new method for measurement of aminolaevulinate dehydratase (EC 4.2.1.24) activity of human erythrocytes. In this method, the amount of substrate δ-aminolevulinic acid consumed (instead of the amount of porphobilinogen formed) is determined colorimetrically. In the incubation mixture, the δ-aminolevulinic acidpyrrole produced by the condensation of δ-aminolevulinic acid with ethyl acetoacetate is separated from porphobilinogen by extraction with ethyl acetate, without resorting to ion-exchange column chromatography. The pyrrole-containing extract is treated with a modified Ehrlich's reagent. Activity of the enzyme is expressed as micromoles of δ-aminolevulinic acid consumed per minute per liter of erythrocytes. Enzyme activity is more accurately estimated by the present method than by the usual method in which porphobilinogen is measured.

[学科分类] 过敏症与临床免疫学