GAMMA-RADIOLYSIS-INDUCED MODIFICATIONS OF LOW-DENSITY LIPOPROTEINS (LDL) - UPTAKE BY APO B GAMMA AND SCAVENGER RECEPTORS, AND CYTOTOXICITY TOWARDS CULTURED HUMAN FIBROBLASTS/

In this work, we investigated the consequences of human low-density li poprotein (LDL) peroxidation initiated by oxyradicals generated by gam ma-radiolysis of water (O-2 degrees(-)/OH degrees), on the recognition of the oxidized LDL by the apo B/E receptor of fibroblasts and the sc avenger receptor of macrophages. Their cytotoxicity towards human fibr oblasts has also been examined. We showed that these oxidized LDL were still recognized by the apo B/E receptor but less than native LDL. Th ey were weakly taken up by the macrophages. They were also cytotoxic t owards human fibroblasts and this effect was dependent on the radiatio n dose. In contrast, no correlation was found between the extent of re cognition by macrophages and the radiation dose, under our experimenta l conditions. These results suggest that the LDL modifications induced by gamma-radiolysis are probably different from those observed with c opper ions. These oxidized LDL might constitute an interesting way to introduce oxidized lipids into the cells.