PHOSPHORUS METABOLISM IN HUMAN ERYTHROCYTE

III. REGENERATION OF ADENOSINE TRIPHOSPHATE IN LONG-STORED ERYTHROCYTE BY INCUBATION WITH INOSINE AND ADENINE

Abstract

1. ATP content of long-stored blood cells was not restored by incubation with inosine alone but a marked increase of ATP level was observed by in-cubation with added adenine together with inosine.
2. By the use of adenine-8-C¹⁴, it was demonstrated that added adenine itself was utilized for the synthesis of adenine nucleotides.
3. Regeneration of ATP was accompanied by a shape change of ery-throcytes from spheric to shallow bowl form.
4. The extent of ATP regeneration in aged erythrocytes can be estimated by measuring P³² incorporation into total nucleotide in the cells. By this procedure was studied the influences of adenine and inosine concentrations, preservation period, and metabolic inhibitors. Arsenate, iodoacetate and fluoride inhibited the reaction strongly.
5. Only adenine was effective among various purines and pyrimidines. When various nucleosides and deoxynucleosides were added to the stored blood supplimented with adenine, purine nucleosides and purine deoxynucleo-sides were effective. The nucleosides and possibly the deoxynucleosides are suggested to provide the pentose residue of the adenine nucleotides and the glycolytic intermediates necessary for the supply of phosphate.
6. These findings lead us to a prospect for extending the useful storage life of aged blood cells.
Authors express their thanks to Dr. Miyamoto, the President of Plasma Laborato-ries, Tokyo, and Dr. Tooyam a of the Blood Transfusion Center of the University of Tokyo Hospital for the generous supply of stored blood.