[Research on high-temperature transition in liposomes made from egg yolk lecithin]

The pyrene eximerization, polarity of pyrene microenvironment and relaxation times (T1 and T2) of water protons in the systems of monolamellar egg yolk lecithin liposomes were investigated depending on temperature and bilayer modification by cholesterol and alpha-tocopherol. The thermotropic transition of pyrene eximerization degree at 38 degrees C, abrupt polarity change of pyrene microenvironment at 22-25 degrees C in modified by tocopherol liposomes and abnormal behaviour of water proton relaxation times in the temperature range of 39-40 degrees C were found. This high-temperature transition is supposed to be due to the structural alteration in the region of egg yolk lecithin heads.