Adenosine metabolism in human erythrocytes

Adenosine Metabolism in Human Erythrocytes

Quantitation of adenosine-5'-triphosphate used for phosphoinositide metabolism in human erythrocytes.

The human erythrocyte actively phosphorylates and dephosphorylates phosphatidylinositol present in the membrane in an apparent "futile cycle." Recent reports have proposed that this phosphorylation/dephosphorylation cycle is a significant consumer of adenosine-5'-triphosphate (ATP) in the erythrocyte. This study details two independent techniques for quantitating the ATP consumed by this phosph...

Studies on the metabolism of adenosine and adenine in stored and fresh human erythrocytes.

By BERTRAM A. Lowi’ AND MARJORIE K. WILLIAMS T HE MATURE human erythrocyte, which is incapable of de novo purine nucleotide synthesis, can utilize preformed purines and purine nucleosides for tile formation of purine nucleotides, in vitro.” 2 Studies in this laboratory have demonstrated that adenine is an effective precursor of the ATP of the human erythrocyte and that hypoxanthine, guanine, an...

The elevation of adenosine-triphosphate levels in human erythrocytes.

It has previously been possible to double the level of ATP in human erythrocytes by incubation of the cells at 37 for 1 0 hr with glucose and adenine. The present study describes a further increase in the ATP level and some of the possible mechanisms involved. Addition of 5 mM pyruvate to a medium containing 32 mM inorganic phosphate, glucose. and adenine elevated the level of ATP threefold dur...

Mechanisms of adenosine 5'-monophosphate catabolism in human erythrocytes.

Uncertainties regarding the role of pyrimidine nucleotidase (PyrNase) in AMP catabolism were resolved by studies of erythrocytes from normal controls, controls with young mean cell ages, and patients with hereditary hemolytic anemia due to severe deficiency of PyrNase. Hemolysates from the latter exhibited undiminished capacity to dephosphorylate AMP over a broad range of pH, indicating that Py...