Effect of products of radiation-induced free radical fragmentation of phospholipids and temperature on lipid membranes

摘要

Thermotropic behavior of liposomes exposed to #gamma#-radiation was studied by differential scanning microcalorimetry. It was found that the peak corresponding to the gel-liquid crystal transition for liposomes composed of bovine brain sphingomyelin and dipalmitoyl phosphatidyglycerol broadened and shifted toward the high-temperature region. No effect of irradiation on dipalmitoyl phosphatidylcholine liposomes was observed. Previously it was shown that, on exposure to #gamma#-rays, sphingomyelin and phosphatidylglycerol, as opposed to phosphatidylcholine,. broke down into fragments of lower molecular weight. It is concluded that the accumulation of products of phospholipid fragmentation in the membrane results in the changes of phase transition parameters.