Adenosine triphosphate release by osmotic shock and hemoglobin A1C in diabetic subjects' erythrocytes

We investigated the significance of adenosine triphosphate (ATP) release from diabetic subjects' red blood cells (RBCs) following osmotic shock (OS) and its possible relationship with hemoglobin A1C (HbA1C) and with the RBC membrane protein skeleton. RBCs from type I (insulin-dependent [IDDM]) and type II (non-insulin-dependent [NIDDM]) diabetic subjects and age- and sex-matched control subjects were submitted to OS using NaCl solutions (from 0.9% to 0.045% final concentration). ATP release values were determined by the bioluminescent method. For pattern study, they were expressed both as absolute values and as percentages (%) of ATP maximum release (at 0.045% NaCl solution). Twenty-seven IDDM and 25 NIDDM subjects and two control groups were investigated. ATP content in RBCs was 2.08 +/- 0.19 pmol/10(4) RBC in IDDM and 1.23 +/- 0.20 pmol/10(4) RBC in NIDDM subjects. The ATP content of IDDM subjects' RBCs was significantly higher than that of the corresponding control group. ATP release at 0.49% NaCI OS, both as absolute value and as percentage value, was significantly lower in both diabetic groups, and ATP% was inversely correlated with HbA1" (IDDM: r = -.489, P < .01; NIDDM: r = -.654, P < .01), suggesting a possible relationship between Hb glycation, RBC membrane protein skeleton glycation, and its influence on ATP release by OS. In conclusion, the proposed method seems useful for measuring RBC ATP content and, at the same time, for monitoring the leak effect of the RBC membrane before it bursts.