Abstract
Serum Apo A-I and A-II levels in 42 cerebrovascular patients, 26 with cerebral thrombosis and 16 with cerebral hemorrhage, and 30 healthy subjects were determined by laser nephelometry. Apo A-I and A-II were purified from delipidated HDL by the combination of gel filtration and ion exchange column chromatography. Antisera against each apoprotein were prepared by injecting rabbits with purified Apo A-I or A-II.
Average serum Apo A-I and A-II concentrations in healthy subjects were 131±17.8mg/dl and 79±10.9mg/dl, respectively, and the calculated A-I/A-II ratio was 1.66±0.18. Apo A-I and A-II levels in thrombotic patients were 103±18.8mg/dl and 50±10.4mg/dl, and the values in hemorrhagic patients were 97±21.5mg/dl and 55±17.7mg/dl, respectively. All of these values were significantly lower than those in the age-matched healthy controls. No statistically significant difference was seen between two groups of patients. Average values of A-I/A-II ratio in thrombotic and hemorrhagic patients were 2.08±0.31 and 1.84±0.37, respectively. These values were significantly larger than the value in controls, and a statistically significant difference was observed between thrombotics and hemorrhagics.
From these results, it was noted that protein components, as well as lipids, of HDL were lower than normal in cerebrovascular patients. In addition to such quantitative changes, qualitative alteration in the composition of HDL, which is reflected in large A-I/A-II ratio, may be a characteristic of lipoprotein metabolism in cerebrovascular patients, and this alteration may be closely related with vascular lesions leading to the outbreak of cerebral thrombosis or hemorrhage.
