DETERMINATION OF CHOLESTEROL AND PHOSPHOLIPIDS OF HDL2 , HDL3 AND VHDL IN PATIENTS WITH ATHEROSCLEROSIS AND DIABETES MELLITUS

This report describes a method for and the results of an analysis of cholesterol and phospholipids in HDL2 and HDL3 and phospholipids in VHDL (d.>1.210) of patients with cerebral thrombosis, myocardial infarction and diabetes mellitus.

After precipitation and elimination of LDL (low density lipoprotein) and VLDL (very low density lipoprotein) by Na phosphotangstate (NaPhT) and MgCl2 and bringing the non-protein density to 1.125, serum was subjected to ultracentrifugation with #494 angle rotor of IEC/B-60 ultracentrifuge (Kubota-International) at 105,000xG for 22 hours.

The inadequate separation between HDL2 and HDL3 was observed at the clear zone beneath the top of fraction after centrifugation under these analytical conditions. Therefore, in this contaminated fraction, the HDL2/HDL3 ratio was calculated by the phospholipids/cholesterol ratio which had been substantially different between HDL2 and HDL3. VHDL-phospholipids was calculated by subtracting HDL3-phospholipids from phospholipids of density higher than 1.125.

The average HDL2-cholesterol and phospholipids levels were 14.8±4.2 and 23.9±5.8 mg/dl respectively in eight healthy men and 18.8±5.0 and 28.5±6.8 mg/dl respectively in seven healthy women. The average HDL3-cholesterol and phospholipid levels were 37.6±7.8 and 57.3±11.0 mg/dl respectively in eight healthy men and 40.3±11.9 and 64.9±22.1 mg/dl respectively in seven healthy women. The average VHDL-phospholipid level was 20.4±5.7 mg/dl in eight healthy men and 21.4±4.8 mg/dl in seven healthy women.

In patients with cerebral thrombosis, not only lipids in HDL2 and HDL3 but also VHDL-phospholipids significantly decreased. In patients with myocardial infarction, although lipids in HDL2 and HDL3 significantly decreased, VHDL-phospholipids maintained the normal value in most cases. In diabetic patients, HDL2 decreased moderately but HDL3 as largely as observed in patients with cerebral thrombosis and myocardial infarction, whereas VHDL-phospholipids were within the normal range.

Among four phospholipids in VHDL fraction, lecithin and lysolecithin were significantly lower in patients with cerebral thrombosis as compared with healthy subjects.