高比重リポ蛋白(HDL)の血管内皮細胞の増殖促進作用に関する研究

Abstract

In cultured bovine pulmonary endothelial cells (EC), human high density lipoproteins (HDL) induced DNA synthesis, which was measured by the incorporation of 3H-thymidine, in the complete absence of the serum. Neither the apolipoprotein components of HDL, apoHDL/cholesterol/DMPC (dimyristoyl phosphatidylcholine) vesicles, not the 25OH-cholesterol stimulated DNA synthesis. Co-incubation with phorbol-12-myristate-l3-acetate (PMA) did not affect the HDL-stimulated DNA synthesis. Diltiazem, one of the calcium channel blockers, inhibited DNA synthesis both in the quiescent and HDL-stimulated EC. The 45Ca2+ uptake was not changed by incubation with HDL. These results suggest that HDL-stimulated DNA synthesis was not directly linked to the activation of protein kinase C or the extracellular Ca3 uptake.The d<1.019g/cm3 fraction and LDL-stimulated DNA synthesis, in the presence of excessive amounts of these or IntralipidsR, did not cause any additional stimulation of DNA synthesis by HDL. Furthermore, oleic acid enhanced DNA synthesis in the quiscent EC, but not in the HDL (1mg prot/ml)-stimulated EC, thereby suggesting that lipoproteins may provide the fatty acids necessary for the proliferation of bovine vascular endothelial cells.