Increase of ATP level in human erythrocytes induced by S-adenosyl-L-methionine

The effect of S-adenosyl-L-methionine (SAM) on the ATP level, the morphology and the deformability of human erythrocytes was investigated and compared with that of adenosine. (i) Upon incubation with SAM, the ATP level increased considerably in fresh cells (in both young and old cells in similar extent) and in stored (partially ATP-depleted) cells. But the incubation with adenosine increased ATP level to a lesser extent. (ii) The incubation of stored cells with SAM hardly affected (or rather decreased) the IMP level, while that with adenosine remarkably increased IMP (and ITP). (iii) The morphology and the deformability of stored erythrocytes were well conserved in spite of the treatment with SAM, as compared with the treatment with adenosine. The echinocytic transformation was induced in old cells to some extent by SAM, while did not in young cells.