Relationship between lead concentration in blood and the activities of erythrocyte pyrimidine 5'-nucleotidase and delta-aminolevulinate dehydratase in the mice exposed to lead.

The relationship between the activities of both pyrimidine 5'-nucleotidase (Py5N) and delta-aminolevulinate dehydratase (ALA-D) in erythrocytes and the concentration of lead in blood was investigated in the mice which were given ad libitum a drinking water containing lead of 10 to 500 ppm, for 30 days. From these results, it was demonstrated that the erythrocyte Py5N activity is inhibited by lead and its activity level is negatively correlated with the concentration of lead in blood (r = -0.78). In addition, it was suggested that the erythrocyte Py5N activity is a better indicator in the exposure to relatively high lead concentration while the ALA-D is a more sensitive indicator for evaluating the lead exposure of low and moderate levels.