Individual variation of nucleoside triphosphate pyrophosphohydrolase activity in human erythrocytes, granulocytes, lymphocytes, and platelets.

Analysis of the nucleoside triphosphate pyrophosphohydrolase specific activity of red cells obtained from a random Caucasian population indicated at least two subclasses. The specific activity of 18% of the population ranged from undetectable activity to 27.5 nmol ITP cleaved/20 min/mg hemoglobin. The remainder of the population had higher activity, 27.5-125 nmoles ITP cleaved/20 min/mg hemoglobin. The variation of NTPH activity evident in the red cells of an individual is reflected in granulocytes, lymphocytes, and platelets of that individual. Erythrocyte activity ranges from 0.7 to 21 units (nmol of ITP cleaved in 20 min)/10(7) cells, granulocytes have 17-201 units/10(7) cells, lymphocytes have 91-462 units/10(7) cells, and platelets have 1.1-7.1 units/10(7) platelets. These cell differences are discussed with respect to the hypothesis that NTPH prevents incorporation of ITP or dITP into nucleic acids.