Kinetic Studies of Lipid Exchanges in Red Cell Membranes in Hereditary High Red Cell Membrane Phosphatidylcholine Hemolytic Anemia : Reference to the Abnormal Accumulation of Phosphatidylcholine in These Membranes
The pathogenesis of the accumulation of phosphatidylcholine (PC) in red cell membranes of the patients with hereditary high red cell membrane phosphatidylcholine hemolytic anemia (HPCHA) was studied utilizing 14C-PC and 14C-lyso-PC. The uptake of 14C-PC was not significantly different in the red cell membranes with HPCHA from that in normal controls and obstructive jaundice in whom red cell membrane PC and free cholesterol (FC) were elevated to the same extent as that in HPCHA. The efflux of 14C-PC with HPCHA was slightly decreased, in comparison with that in the normal controls and obstructive jaundice. The most striking data were obtained in the uptake of 14C-lyso-PC by the red cells of the HPCHA patients, showing more than two fold increase when compared with that in the normal control. The conversion of 14C-lyso-PC to 14C-PC was increased in comparison with that in the normal controls and obstructive jaundice. In summary, the exact cause of the abnormal accumulation of PC through increased uptake of lyso-PC, followed by the increased conversion of lyso-PC to PC is unknown. In obstructive jaundice of an acquired origin, some compensatory mechanism may exist to prevent the further accumulation of lipids in the red cell membranes.