Studies on the Metabolism of Adenosine and Adenine in Stored and Fresh Human Erythrocytes

The metabolism of adenosine-8-C¹⁴, at relatively high and low concentrations, was studied in human erythrocytes freshly obtained and after 6 and 9weeks of storage in ACD. At high adenosine concentration (3.6 µM/ml. cells),considerable conversion to ATP was found in fresh and stored cells, suggestingthat direct phosphorylation of adenosine occurred, a reaction that is minimalat low (0.36 µM/ml. cells) adenosine concentration because of extensive rapiddeamination. Incorporation of the label via hypoxanthine or adenine is unlikely,since at high adenosine concentration no dilution of ATP labeling in thepresence of unlabeled inosine (hypoxanthine) was found, nor was free labeledadenine detected in erythrocyte extracts.

A study of the metabolism of adenine-8-C¹⁴ in fresh and stored erythrocytessuggests that the presence of a suitable nucleoside (e.g., inosine) is requiredfor efficient utilization of adenine-8-C¹⁴ for ATP formation in the erythrocytesof blood stored for prolonged periods.

Submitted on June 24, 1965 Accepted on August 23, 1965