- 作者: R. Masella; A. Cantafora; D. Maffi; R. Volpe; M. G. Ginnetti; G. Ricci; N.L. Mace; G.M. Buxton; S.W. Peterson
- 作者服務機構: Istituto Superiore di Sanita, Laboratories of; a Metabolism and Pathological Biochemistry, and; b Clinical Biochemistry, Rome;; c Istituto di Terapia Medica Sistematica, Universita 'La Sapienza', Rome, Italy;; d Arkansas College, Batesville, Ark., USA
- 中文摘要: --
- 英文摘要: The aim of this study was to determine whether the common forms of dyslip- idemia could affect either the lipid composition or insulin receptor processing (down-regulation) of erythrocytes. The study included 22 patients with type IIa hypercholesterolemia, 15 patients with type IV hypertriglyceridemia and 12 patients with type IIb hyperlipidemia. Ten normolipidemic subjects were used as controls. Their erythrocyte membranes were analyzed for lipid compo- sition and insulin receptor down-regulation. The results show that all the hyperlipidemias investigated were characterized by significant increases in the cholesterol to phospholipid molar ratio (0.56 ?0.08 in controls and 1.11 ?0.13, 1.09 ?0.14, 1.04 ?0.15, p< 0.001, in types IIa, IIb and IV, respective- 1y). Surface insulin receptors of type IIa and IIb patients did not appear to down-regulate when compared to normal subjects, but rather up-regulated (+ 65.2% in controls, - 1.0% and -8.7%, p< 0.001, in type IIa and IIb patients, respectively). Patients with type IV hypertriglyceridemia showed a residual capacity for insulin receptor internalization (10.7% down-regulation). Mem- branes of all the patients contained a higher proportion of phosphatidyletha- nolamine; the molar ratio of sphingomyelin to phosphatidylcholine was signif- icantly higher in types IIb than in controls (1.22 ?0.11 and 1.12 ?0.10, p < 0.05, respectively); all the patients showed a lower content of polyunsaturated fatty acids in the major glycerophospholipid classes. However, type IV hyper- triglyceridemics showed less variations, especially in the phosphatidylserine fraction. These results indicate that the alterations in lipoprotein pattern may affect both the lipid membrane equilibria and the processing ability of surface insulin receptors.
- 中文關鍵字: --
- 英文關鍵字: Cholesterol; Erythrocyte membrane; Hypercholesterolemia; Hypertriglyceridemia; Insulin receptor; Phospholipid