EFFECTS OF PEROXYNITRITE ON PLASMA COMPONENTS OF THE REVERSE CHOLESTEROL TRANSPORT PATHWAY

Elimination of cholesterol from arterial tissue, crucial in limiting a therogenesis, may be achieved via high-density lipoprotein (HDL)-media ted reverse cholesterol transport (RCT); components of this pathway ca n be modulated by oxidative stress. Here we have examined the relation s between cholesterol efflux, esterification and transfer in human pla sma treated with the powerfully reactive nitrogen species, peroxynitri te. Cellular cholesterol efflux to whole plasma, or to peroxynitrite-m odified HDL3, was relatively insensitive to peroxynitrite, as,vas the transfer of esterified cholesterol. However, plasma cholesterol esteri fication, via lecithin:cholesterol acyltransferase (LCAT), was markedl y inhibited, both directly and indirectly, by peroxynitrite treatment, implying inefficient RCT follows HDL sequestration of cellular choles terol. (C) 1998 Federation of European Biochemical Societies.