Abstract: | The ATP content in human erythrocytes depleted without glucose falls down to half of the initial value within 2-3 hours and reaches practically zero within more than 10 hours. The ADP content increases 2-3-fold during the 1st hour after depletion and then slowly decreases. The AMP content increases 10-fold during several hours, but the rate of this process constantly decreases. The adenylate pool decreases at a constant rate ranging from 0.13 to 0.25 mmol/l cell. h; this is accompanied by accumulation of IMP. Addition of glucose to depleted erythrocytes results in partial recovery of the ATP level within 1-2 hours. The sooner glucose addition after the depletion, the greater the recovery. Simultaneously the ADP and AMP levels drastically decrease to new constant values. The decline of the adenylate pool ceases and the rate of IMP accumulation increases. Normally, the [ATP]/adenylate pool ratio lies within the small interval 0.85-0.94 irrespective of significant individual differences in the absolute values of [ATP]. This ratio is decreased during depletion and restored to the initial value after glucose addition. The mass-action ratio of the adenylate kinase reaction changes greatly during depletion and restoration of erythrocyte ATP. |