A chip calorimetry-based method for the real-time investigation of metabolic activity changes in human erythrocytes caused by cell sickling

A new calorimetric technique is described which allows the measurement of metabolic heat rates in biological materials which are triggered by changes in the oxygen tension. It uses the high permeability for oxygen of a thin-walled Teflon flow channel of a chip calorimeter in order to adjust variable but defined oxygen concentrations in the samples. Using this technique, for the first time, the heat production rate of sickle cell erythrocytes (SS-RBCs) in sickled and non-sickled state could be compared. To measure heat rate changes in real time when sickled SS-RBCs return to the non-sickled state, the heat dissipation was measured during the re-oxygenation of the cell samples which had been treated before under anoxic conditions. We found higher heat production rate of the blood cells in non-sickled state, which is in agreement with the reported increased glucose uptake.