FURTHER OBSERVATIONS ON ERYTHROCYTE PYRIMIDINE- NUCLEOTIDASE DEFICIENCY AND INTRACELLULAR ACCUMULATION OF PYRIMIDINE NUCLEOTIDES

A B S T RA C T Pyrimidine nucleotides, detectable in normal erythrocytes only in trace quantities if at all, were found to comprise 7-80% of the intracellular nucleotide pools in nine subjects with severe lead overburden. Blood lead concentrations ranged from -200to 400-,ug/dl packed cells, and the greatest accumulations ofpyrimidine-containing nucleotides occurred in the two subjects with the highest blood lead levels. Most of the patients had mild or moderate anemia and moderate basophilic stippling evident in Wright'sstained peripheral smears. Pyrimidine nucleotidase activities were inhibited to 13-28% of the mean activity in normal control erythrocytes and even more so (5-15%) when compared to specimens with increased reticulocytes and young cells. Reticulocytosis was absent in two subjects and modest to moderate in the remainder, but erythrocyte assays revealed the substantial elevations in glucose-6-phosphate dehydro