Factors affecting inosinate synthesis and inosine triphosphate accumulation in human erythrocytes.

Measurements of rates of inosinate synthesis from radioactive hypoxanthine by human erythrocytes show a large degree of individual variation. Rates of inosinate synthesis also vary with the pH and phosphate concentration of the incubation medium. This may be due to changes in the rate of phosphoribosyl pyrophosphate synthesis, and the stimulatory effect of phosphate on this process seems to be more important than the inhibitory effect of 2,3-diphodphoglycerate. The rate of inosinate synthesis, and especially the extent of accumulation of inosine triphosphate, increase disproportionately with time of incubation up to at least 24 h. Storage of erythrocytes also tends to increase inosinate synthesis and inosine triphosphate accumulation.