HUMAN RESPONSES TO LEAD IN SPECIAL REFERENCES TO PORPHYRIN METABOLISM IN BONE MARROW ERYTHROID CELLS, AND CLINICAL AND LABORATORY STUDY

Abstract

Enzymatic studies on heme biosynthesis in erythroid cells of bone marrows ob-tained from ten lead workers were carried out after the establishment of methods.
A remarkable reduction of the activities of δ-aminolevulinic acid (ALA) dehydrase and heme synthetase, a slight elevation of ALA synthetase activity, and a parallel reduction of ¹⁴C-glycine incorporation into heme and globin were observed. Abnor-malities found in hematological examinations and in urinary or erthrocyte porphyrin metabolism were discussed in connection with both the above mentioned results and the human response to lead.
Clinical and laboratory examinations on these workers revealed a commonly exist-ing hypertension, ECG abnormalities, reduced renal functions, especially those of renal blood circulation and of renal tubules, EMG abnormalities, a reduced conduction velo-city of long nerves, and elevated concentrations of urea-N and uric acid in serum. The pathogenesis of these findings were also discussed.