抄録
Serum lipoprotein(a) {Lp(a)} is accepted as a potent risk factor for atherosclerotic disease. C4b binding protein (C4bp), a regulatory protein in complement system, plays important roles in blood coagulation and fibrinolysis, and is identical with proline-rich protein. Our previous study showed a positive correlation between serum Lp(a) and C4bp levels (Nagata et al., J. Jpn. Atheroscler. Soc., 20: 651-655, 1992). Both the serum amyloid A (SAA) and serum amyloid P (SAP) components are precursors of the amyloid A and P proteins, which are the main amyloid components deposited in the tissue of secondary amyloidosis. In human blood, SAP binds with C4bp, and SAA binds with HDL lipoprotein.
We examined effects of oral administration of niceritrol (750mg/day, for 16 weeks) on serum lipids, apolipoproteins, Lp(a), C4bp, SAP, and SAA in 26 patients (12 males and 14 females) who had high serum Lp(a) levels (>30mg/dl) and the following cerebrovascular diseases: cerebral infarction (16 patients), cerebral bleeding (8 patients), and subarachinoidal hemorrhage (2 patients).
Niceritrol therapy decreased total cholesterol and triglyceride levels, confirming previous reports. HDL-cholesterol levels had increased 4 weeks after administration, but the increases after 16 weeks were not significant. Apolipoproteins B and C-III levels had decreased after 16 weeks, but other apolipoproteins showed no significant change.
Niceritrol obviously lowered serum Lp(a) levels; the percentage decrease from the pre-treatment level was 22±8% (12±4mg/dl) after administration for 16 weeks. Lp(a) levels rebounded to pre-treatment levels 4 weeks after niceritrol therapy was discontinued. C4bp levels had also decreased after 4 weeks, but the decreases after 16 weeks were not significant. However, the percentage decreased in Lp(a) and C4bp levels showed a positive correlation. In addition, both SAA and SAP levels decreased after 16 weeks, and the decreases, in percentage terms, percentage were positively correlated. Niceritorol therapy lowered the serum levels of C4bp, SAA, and SAP as well as Lp(a). We speculate that niceritrol suppressed the production of these proteins in the liver.
