CALCULATION OF VANT HOFF ENTHALPY ASSOCIATED WITH ASPIRIN-INDUCED CHANGE IN LIPOSOMAL MEMBRANE ANISOTROPY

The lipid disordering effect of aspirin on the liposomal membrane of d ipalmitoyl phosphatidyl choline has recently been studied using the fl uorescence polarization method. From the anisotropy-temperature curve, we have calculated here the associated change in van't Hoff enthalpy. Since the fluorescence technique requires a very small amount of samp le (10(-4) M), this method of enthalpy calculation compares well and i s advantageous over the standard calorimetric methods.