The relationship between LDL oxidation and macrophage myeloperoxidase activity.
OBJECTIVE
To explore low density lipoprotein (LDL) oxidation by macrophage myeloperoxidase (MPO) at molecular level.


METHODS
Using a mouse macrophage model, we examined the relationship between LDL oxidation and macrophage MPO by measuring macrophage MPO activity, LDL oxidation products, MPO gene expression and cellular orientation of LDL oxidation.


RESULTS
MPO gene expression increased to its maximum gradually when the concentration of LDL was increased, and then maintained at that level. NaN(3) inhibied the elevation of MPO activity and LDL oxidation, which was LDL concentration-dependent. After the composition of macrophage membrane was roughly analyzed, it was determined that the contents of MPO and LDL in 5% sucrose were 7.667 and 21 times higher than those in 10% sucrose, respectively.


CONCLUSIONS
LDL is attached to the "microdomain" of the macrophage membrane in which LDL is oxidized by MPO.
Wu
Junzhu
J
Department of Biochemistry, College of Medicine, Wuhan University, Wuhan 430071, China.
Liu
Yanhong
Y
Li
Xiaoming
X
Chen
Lida
L
Xia
Laju
L
Hong
Jialing
J
D000818:Animals; D008077:Lipoproteins, LDL / Q000378:metabolism*; D008264:Macrophages / Q000378:metabolism*; D051379:Mice; D010084:Oxidation-Reduction; D009195:Peroxidase / Q000235:genetics / Q000378:metabolism*
D008077:Lipoproteins, LDL; D009195:Peroxidase