1978 Volume 6 Issue 1 Pages 1-8
Recent advances in immunological method have facilitated the determination of serum lipprotein in easy. The clinical usefullness of the determination of β-lipoprotein by this method is widely recognized and now the immunological assessment of α1 lipoprotein which means α-lipoprotein with α1 mobility is also inclined to be adopted practically. The purpose of this study is to establish the most suitable procedure to assess serum α1lipoprotein by single radial immunodiffusion method and to clarify the significance of α-lipoprotein in atherosclerotic disorders with special reference to cerebrovascular diseases.
The best procedure established was as follows:
Three μl of sera diluted to 1:10 with veronal-HCl buffer (pH 8.6) were dropped into the hohle on one plate which consist of 5ml of 3% agarose and 5ml of 20% anti α1lipoprotein rabbit serum in the buffer. The plate was incubated for 48 hours at 37°C. Area of precipitation ring formed on the plate was designated as the concentration of serum α1lipoprotein. The coefficient of variation in this method was 1.62% in ten replicate on one and the same day.
Concentration of serum α1lipoprotein decreased markedly following storage at 4°C and even-18°C indicating the necessity of instant assessment (Fig. 1).
Subjects examined consist of 145 cerebrovascular patients and 245 non-cerecrovascular controls. In controls with neither hypertension, abnormal ECG findings nor hyperlipidemia, serum α1lipoprotein levels were significantly higher in the aged over 60 than that in the aged under 39 (Fig. 2), and the values in hyperlipidemia were higher compared to normolipidemics (Fig. 3). In normolipidemic controls with hypertension, the value was lower than that in normotensives aged over 60.
Patients' levels were not affected by their age, blood pressure, and other serum lipid levels, and significantly lower than that of controls (Fig. 2). The value of patients complicated with abnormal ECGs and renal impairment was significantly lower than that of patients without these findings (Fig. 4). The values of patients with cerebral infarction was lower than that with cerebral hemorrhage, however, the difference was not significant.
α1Lipoprotein was directly proportional to total cholesterol, malondialdehyde and antithrombin III in patients (Fig. 5).
These results indicating the low level of serum α1lipoprotein in cerebrovascular disorders were in agree with those in previous observations of HDL by the ultracentrifugal method. Therefore, the results obtained comfirmed further the close relation of α-lipoprotein to atherosclerotic disorders including cerebrovascular diseases and the clinical usefullness of single radial immunodiffusion method.
It has been emphasized that the inhibitory effect of α-lipoprotein to atherogenesis is based on the removal of cholesterol from arterial wall. The directly proportional relationship between α1lipoprotein and total cholesterol in controls in our results supports this concept. In addition, the significant relationship between α1lipoprotein and malondialdehyde suggests inhibitory effects of α1 lipoprotein on thrombogenesis which is affected by lipoperoxides. Possible important role of α-lipoprotein in the regression of atherosclerosis is also assumed by many evidence. Therefore, further intensive observation of α1lipoprotein in atherosclerotic disorders should be performed.
