Critical evaluation of the quantification of ATP release reaction in whole blood

The influence of erythrocyte and thrombocyte content on the release of adenosine triphosphate (ATP) in whole blood was tested. Citrated blood from 39 healthy persons was diluted gradually. The release reaction was induced by arachidonic acid (1.25 mM), adenosine diphosphate (ADP; 30 microM) and collagen (1.0 and 5.0 micrograms/ml). The peak of the obtained curves was transformed into percent values of the maximal deflection by the undiluted sample (PEAK IN RELATION) and into ATP concentrations (ABSOLUTE PEAK). By rising dilution an increase of the peak in relation with all inducers was observed which was mainly due to the luminescence-optical effect. As expected the absolute peak decreased but only under arachidonic acid and collagen. Under ADP despite of the rising dilution constant amounts of ATP were released suggesting an additional release from other blood cells. High ATP release curves in response to ADP were observed in patients with pancytopenia and with thrombocytopenia when compared to health persons. ADP seems not to be suited for the measurement of ATP release reaction in whole blood. Collagen at a final concentration of 1.0 micrograms/ml was found as the optimal inducer. The ATP standard is essential for the quantification of release reaction.