脳血管障害後遺症患者における血清リポ蛋白の polyacrylamide gel disc 電気泳動分析

Abstract

Polyacrylamide gel disc electrophoresis of lipoprotein in sera of 123 cerebrovascular patients and 138 non-cerebrovascular controls was carried out by means of the prestaining method developed by Narayan et al. and Wada et al. and ameliorated by authors. Glass column with a length of 100mm and internal diameter of 7mm was used. Polyacrylamide gel solution was prepared by Tris-HCl buffer. Concentrations of polyacrylamide of lower and upper separating and spacer gel solution were 7.5%, 3.75%, and 2.5% respectively, and pH of separating and spacer gel solution were 8.8 and 6.7. Amounts of the gel solution pipetted into the lower and upper separating and the spacer layer were 0.5ml, 0.6ml and 0.1ml. The sample layer was not prepared. Lipoprotein was stained over night at 4°C by mixing serum with a half volume of 0.5% Sudan Black B solution in ethylene glycol before the electrophoretic procedure. Thirty μl of the sample, the mixture of prestanned serum with equal amount of the solution prepared by adding one volume of Tris-HCl buffer (pH 6.7) to three volumes of 20% sucrose solution, was pipetted into the sample layer. Electrophoresis was performed in Tris-glycine buffer (pH 8.3) for about 70 minutes by 4mA per a column.Serum total cholesterol and triglyceride levels in subjects with presence of mid-bands were higher than in those with absence of the bands. Higher pre β-lipoprotein and lower α-lipoprotein concentrations in the cellulose acetate membrane electrophoresis were indicated in subjects with presence of mid-bands than in those with absence of the bands. In all subjects examined, mid-bands were detected in 88 of 123 patients (71.5%) and in 60 of 138 controls (43.5%), the incidence in patients was significantly higher than controls. Mid-bands were found more frequently in patients with cerebral infarction, with abnormal ECG findings and with impaired renal functions than in those with cerebral hemorrhage, with normal ECG findings and with normal renal functions. In controls mid-bands were found in 17 of 24 hyperlipidemics (70.8%) and 43 of 114 normolipidemics (37.7%), the significantly higher incidence in the hyperlipidemics than the normolipidemics was indicated. In patients the difference in these incidences was not found. In normolipidemic subjects mid-bands were found in 66 of 98 patients (67.3%), the incidence in patients was significantly higher compared with the value of 37.7% in controls, and mid-bands were also significantly more frequently found in patients with clinical findings manifested by atherosclerotic changes than in those without the findings.In recent papers mid-bands are regarded as intermediate products in the metabolic process between pre β-, and β-lipoprotein which is formed from pre β-lipoprotein. Our data indicating the close relation of serum triglyceride level and pre β-lipoprotein concentration to mid-bands support these concepts. Significantly high incidence of midbands in normolipidemic patients suggests the close relation of the band to atherosclerotic disorders and the existence of abnormal lipoprotein metabolism in cerebrovascular disease. Although many papers representing the low serum lipid levels and the minor role of hyperlipidemia in cerebrovascular disorders in Japan have been published, it is not satisfactory to estimate the serum lipid levels in the investigation of lipid metabolism in cerebrovascular patients. The results obtained show the importance of qualitative observations of serum lipids in cerebrovascular disorders, therefore, studies on lipid in cerebrovascular disorders should be never disregarded.