Experimental low density lipoprotein (LDL) oxidation is usually performed u
sing trace copper, although the in vive relevance of this method has been c
alled into question. Such LDL augment adenosine 5'-diphosphate (ADP) induce
d platelet aggregation, presumably by the action of lipid derived compounds
. In striking contrast, we find that LDL oxidized to a comparable extent by
hypochlorite, an in vive occurring oxidant, reveal themselves to be potent
promoters of platelet aggregation. Interestingly, hypochlorite modified LD
L seem to mediate their influence on human platelets by means of the modifi
ed apolipoprotein B-100 (apoB) moiety. Also, the finding that hypochlorite
modified albumin is able to trigger platelet aggregation suggests an essent
ial role for hypochlorite modified protein(s) in the process of platelet ac
tivation. (C) 2000 Federation of European Biochemical Societies. Published
by Elsevier Science B.V. All rights reserved.