The ADP and ATP Levels and the Phosphorylating Activity of Erythrocytes in Patients with Uremia Associated with Chronic Renal Failure

Abstract

The ADP and ATP levels of erythrocytes were determined by the column-chromatography in patients with uremia associated with chronic renal failure, in order to study the mechanism of the increased hemolysis in uremia. The in vitro incorporation of radiophosphorus in ADP and ATP of erythrocytes was also studied. The ADP and ATP levels of erythrocytes were slightly elevated in patients with uremia, averaging 11.9 mg/100 ml erythrocyte and 98.1 mg/100 ml erythrocytes, respectively. The ATP/ADP ratio was within normal limits. When normal erythrocytes were incubated with P32 in vitro for 15 minutes at 37[degree]C, no radioactivity was demonstrated in the 5/1,000 N HC1 fraction containing inorganic phosphorus and AMP. However, when erythrocytes of patients with uremia were incubated with P32 for 15 minutes, a large amount of radioactivity was still present in the 5/1,000 HC1 fraction. The in vitro incorporation of radiophosphorus in ADP and ATP of erythrocytes was markedly reduced in patients with uremia. These results demonstrate the decrease of the phosphorylating activity of erythrocytes in patients with uremia. When normal erythrocytes were suspended in uremic plasma and incubated with radiophosphorus, the in vitro incorporation of P32 was markedly reduced, suggesting the inhibitory effect of the increased non-protein nitrogen or toxic products in uremic plasma on the phosphorylating activity of erythrocytes. It seems likely that this decrease of the phosphorylating activity of erythrocytes might play some roles in the mechanism of the increased hemolysis in uremic patients.