Cyclophosphamide-induced changes in plasma and red blood cells detected by differential scanning calorimetry (DSC) in guinea pigs

Cyclophosphamide is one of the most widely used drugs, but it has severe side effects. Considering the variability of kinetics and metabolism of cyclophosphamide in the daily use, it is an important question how could we predict these undesirable consequences. The purpose of this study was to introduce calorimetry for the first time in the detection of cyclophosphamide-induced changes in plasma and red blood cells in an experimental animal model. Adult guinea pigs (n = 55, in 11 different groups) were injected intraperitoneally with the dose of cyclophosphamide that is comparable to the human dosage. Animals were euthanized; plasma and formed elements of blood were analyzed by a SETARAM Micro DSC-II calorimeter. The denaturation temperatures were measured, and the calorimetric enthalpies were calculated based on the areas under thermal absorption curves. The results show a definite dose dependence in both denaturation temperature and calorimetric enthalpy, that is, the DSC seems to be a suitable technique to detect the damage caused by chemotherapy.