[Metabolism and distribution of phosphatidylcholine in membranes of normal and tumor cells].

Data are reviewed on the content, exchange and distribution of exogenously injected phosphatidyl choline in microsomes and mitochondria of normal and tumour cells. Differences in quantity and lipid specificity of phospholipids in tumour cells can be explained on the basis of changes occurring during the processes. The high level of phosphatidyl choline (PC) in mitochondria and low one in microsomal membrane of tumour cells are shown to be bound with elevated capacity of microsomes to spontaneous PC exchange, high PC-transfer activity of the supernatant fraction (pH 5.1; 105000 g) resulting in fast transport of PC into mitochondria. Mitochondria of tumour cells uptake exogenously injected PC twice more intensively than the normal ones. The problem on the role of lipid content and physicochemical properties of donor and acceptor membranes in PC-metabolism are discussed. Membrane modification (administration of cholesterol, trypsin) influences the PC exchange; changes of microviscosity brings about the exchange, but the interrelation is of very complicated character. The obtained data suggest that the PC exchange is associated with the capacity of microsomal lipids of peroxide oxidation.