title: Erythrocyte membrane alterations and plasma lipids in patients with chylomicronemia and in Tangier disease.
abstract: The relationship between erythrocyte membrane structural and functional alterations and plasma lipids was studied in three patients with chylomicronemia due to either lipoprotein lipase (LPL) deficiency, apo C-II deficiency (in an individual who also suffers from thalassemia minor) or coexistent diabetes mellitus (and decreased LPL activity) and in a patient with Tangier disease. All of the patients' erythrocytes had significantly elevated phosphatidyl-choline (PC): sphingomyelin (Sph) ratios (most marked in the patient with Tangier disease). Major differences were observed in the PC: Sph ratios of erythrocytes and plasma. The pattern of changes in erythrocyte membrane enzyme activities differed despite similarities in the lipid composition of the erythrocytes. The changes in osmotic fragility (OF) were inversely related to the membrane cholesterol:phospholipid ratio. An even stronger negative correlation was found between OF at the lowest NaCl concentrations and the activities of both Na+,K+- and Mg++-ATPases. The ratio of total: surface sulfhydryl titres also correlated significantly with OF.
mesh_terms: D000293:Adolescent; D000328:Adult; D053304:Apolipoprotein C-II; D001056:Apolipoproteins C / Q000172:deficiency; D017301:Ca(2+) Mg(2+)-ATPase / Q000502:physiology; D002914:Chylomicrons / Q000097:blood*; D003924:Diabetes Mellitus, Type 2 / Q000097:blood; D004910:Erythrocyte Membrane / Q000032:analysis / Q000201:enzymology / Q000648:ultrastructure*; D006801:Humans; D007009:Hypolipoproteinemias / Q000097:blood*; D008055:Lipids / Q000032:analysis / Q000097:blood*; D008071:Lipoprotein Lipase / Q000172:deficiency; D008297:Male; D008875:Middle Aged; D010713:Phosphatidylcholines / Q000032:analysis; D000254:Sodium-Potassium-Exchanging ATPase / Q000502:physiology; D013109:Sphingomyelins / Q000032:analysis; D013631:Tangier Disease / Q000097:blood*
chemical_list: D053304:Apolipoprotein C-II; D001056:Apolipoproteins C; D002914:Chylomicrons; D008055:Lipids; D010713:Phosphatidylcholines; D013109:Sphingomyelins; D008071:Lipoprotein Lipase; D017301:Ca(2+) Mg(2+)-ATPase; D000254:Sodium-Potassium-Exchanging ATPase