[Transmembrane migration of phosphatidylcholine and peroxidation of lipids in rat liver microsomes].
The exchangeability of phosphatidylcholine in microsomes differing in the degree of lipid peroxidation was determined by incubation of microsomes labelled in vivo with [methyl-14C]choline chloride with an excess of phosphatidylcholine liposomes and phosphatidyl-exchange protein from beef liver. The phosphatidylcholine peroxidation products were shown to act as substrates for the phosphatidylcholine-exchange protein. The level of exchangeable microsomal phosphatidylcholine did not depend on the degree of lipid peroxidation in the microsomes. Stimulation of lipid peroxidation by Fe2+-ascorbate or inhibition of lipid peroxidation by alpha-tocopherol did not influence the exchange of microsomal phosphatidylcholine. However, with highly peroxidized phosphatidylcholine liposomes as acceptor particles the exchange of microsomal phosphatidylcholine in the presence of phosphatidylcholine-exchange protein was strongly inhibited. In all cases the percentage of microsomal phosphatidylcholine exchangeable within 1-2 hrs was 85-90%. It is concluded that lipid peroxidation is not responsible for the rapid translocation (flip-flop) of phosphatidylcholine in rat liver microsomes. A possible involvement of membrane proteins in this process is proposed.
D000727:Androgen-Binding Protein; D000818:Animals; D001692:Biological Transport; D002352:Carrier Proteins / Q000378:metabolism; D002417:Cattle; D007425:Intracellular Membranes / Q000378:metabolism*; D007700:Kinetics; D008054:Lipid Peroxides / Q000378:metabolism*; D008081:Liposomes; D008099:Liver / Q000378:metabolism; D008862:Microsomes, Liver / Q000378:metabolism*; D010713:Phosphatidylcholines / Q000378:metabolism*; D049294:Phospholipid Transfer Proteins; D060789:Prostatein; D051381:Rats; D060765:Secretoglobins; D014598:Uteroglobin; D060788:Mammaglobin B
D000727:Androgen-Binding Protein; D002352:Carrier Proteins; D008054:Lipid Peroxides; D008081:Liposomes; D010713:Phosphatidylcholines; D049294:Phospholipid Transfer Proteins; D060789:Prostatein; D060765:Secretoglobins; D014598:Uteroglobin; C511484:Scgb1d2 protein, rat; C511483:Scgb1d4 protein, rat; C556468:Scgb2a1 protein, rat; D060788:Mammaglobin B
Transmembrannaia migratsiia fosfatidilkholina i perekisnoe okislenie lipidov v mikrosomakh pecheni krysy.