Different Behaviors of Erythrocyte δ-Aminolevulinic Acid Dehydratase

Abstract

Different characteristics of erythrocyte δ-aminolevulinic acid dehydratase (ALA-D) between the workers with the history of occupational lead exposure and normals are described.

In the blood of lead workers, when the hemolysates are heated at 60 C for five minutes, the activity of the erythrocytes ALA-D increases up to about 3.6-fold of an initial level, and as a result of heating the optimum in pH-activity curve changes from pH 6.0 to pH 6.6, which is similar to the optimum pH of normal ALA-D. On the contrary, in normal blood, the optimum in the pH-activity curve is but little changed, even though the erythrocyte ALA-D activity is increased up to about 1.3-fold of the initial level by heating the hemolysates at 60 C for five minutes.